Shiga toxin-producing Escherichia coli in beef

Prevalence and risk factors of Shiga toxin-producing Escherichia coli serotypes in beef at abattoirs and retail outlets in Gauteng

Industry Sector: Cattle and Small Stock

Research focus area: Red Meat Safety, Nutritional Value, Consumerism and Consumer Behaviour

Research Institute: Department of Production Animal Studies, University of Pretoria

Researcher: Prof. Peter Thompson Ph.D.

The Research Team


Year of completion : 2017

Aims of the project

  • To determine the prevalence O157 and non-O157 Shiga-toxin producing Escherichia coli (STEC) in beef abattoirs in Gauteng
  • To determine the prevalence O157 and non-O157 STEC in beef and beef products at retail outlets in Gauteng
  • To identify the important STEC serotypes present in beef and beef products in Gauteng
  • To identify risk factors for STEC contamination of carcasses and beef products in Gauteng

Executive Summary

Shiga toxin-producing Escherichia coli (STEC), particularly the O157 strains, are food-borne zoonotic pathogens of public health importance worldwide. Foods of cattle origin have been implicated in various outbreaks and epidemiological studies have revealed that cattle are major reservoirs of STEC. We conducted cross-sectional surveys from Nov 2015 to Nov 2016, to investigate the prevalence and molecular characteristics of O157 and non-O157 strains of STEC in beef and beef products in the Gauteng province of South Africa.

A total of 265 swab samples of beef carcasses from 12 abattoirs and 399 beef products from 31 retail outlets were screened for STEC using a multiplex PCR. The overall prevalence in abattoir samples was 37% (55/149) in summer and 34% (39/116) in winter. In beef products at retail outlets it was 20% (27/137) in autumn, 14% (18/130) in winter and 17% (22/132) in summer; the highest prevalence was detected in boerewors (35%) followed by mincemeat (21%). The predominant serotypes detected were O113 (19.4%) and O157 (14.9%) in beef products, and O113 (14%) from abattoirs.

Our results demonstrate that STEC is present in South African beef and beef products, and that this may pose a real food-borne disease threat. Further investigation of the epidemiology of the pathogen is required; it is proposed that this take the form of longitudinal studies to investigate the prevalence of shedding of STEC by cattle in the feedlot, following them through to the abattoir to determine factors associated with carcass contamination.

Additional Comments

As this is part of a PhD project, further molecular work is still to be done on the isolates, resulting in further planned publications. The samples also provided material for an MSc student (funded by UP research funds) to work on Salmonella contamination – these results will also be made available to RMRDSA once finalized.

Popular Article

Assessing the prevalence of shiga toxin-producing escherichia coli in beef at abattoirs and retail outlets in gauteng

Dr Lorinda Frylinck, Senior Navorser, LNR-Diere Produksie, Irene.


The production of safe and wholesome beef and beef-derived food products is the highest priority for the beef industry in South Africa. There are potential risks associated with the possible presence of harmful pathogens in the food production chain; however, clear guidelines and regulations have been implemented to reduce these risks to a minimum and ensure a safe product for consumers. Nevertheless it remains important to continually assess these risks and to ensure effective implementation of control measures.

Shiga toxin-producing Escherichia coli (STEC) are bacteria associated with food and waterborne diseases and have been recognized as causing public health problems worldwide. The WHO Foodborne Disease Burden Epidemiology Reference Group (FERG) reported that ‘Foodborne STEC’ caused more than 1 million illnesses and 128 deaths in 2010 (8).

Of the over 470 different serotypes of STEC detected in humans, the O157:H7 serotype is the most frequently associated with large food and water-borne outbreaks (7). However, non-O157 STEC have been increasingly isolated from cases of haemorrhagic colitis (severe GIT infection and bloody diarrhoea) and as well as some fatal kidney failure (HUS; haemolytic uraemic syndrome) cases.

Although the first report of the occurrence of HUS in South Africa dated as far back as 1968 (6), the causative agent was poorly understood at that time. The first clinically proven incidence of E. coli O157:H7 in South Africa was later linked with haemorrhagic colitis (3). The importance of the pathogen in South Africa and other southern African countries has, however, been highlighted by subsequent major outbreaks of bloody diarrhoea in which E. coli O157 strains were implicated (4). Of particular interest was a study in Gauteng province in 2011, in which 7.7% of children with diarrhoea were positive for E. coli O157 (5).

Epidemiological investigations have revealed that cattle are a major reservoir of STEC. Many outbreaks of E. coli O157:H7 have been associated with beef, in particular ground beef, and analyses of some cases have identified undercooked beef as a significant risk factor. However, the fact that E. coli-associated conditions in humans, such as HUS, are not as yet notifiable in South Africa may mean that the occurrence of STEC-associated disease in humans is under-reported. In addition, given the weight of evidence from elsewhere in the world, it is possible that contamination of beef products is also a risk factor in South Africa.

Research problem and objectives

There is a dearth of current information on the frequency of occurrence of O157 and non-O157 strains of STEC, and on the risk they pose to consumers of beef products, in South Africa. Hence, the objective of this study was to determine the prevalence and characteristics of O157 and non-O157 STEC strains in beef carcass and beef products sold at retail outlets in the Gauteng province of South Africa.

Materials and Methods

During a one-year period from Nov 2015 to Nov 2016, two independent cross-sectional surveys were carried out to determine the prevalence of STEC at abattoirs as well as at retail outlets where beef-based food products are sold.

Study 1: Twelve abattoirs (six high throughput and six low throughput) were selected and each was visited during summer and winter months for sample collection. Five animals were randomly selected in each abattoir and tagged for sample collection. Firstly, samples were collected by swabbing the skin of the perineal area immediately after slaughter. Thereafter, carcass swab samples were collected from different parts of the carcass at various stages during processing, including pre-evisceration, post-evisceration, post-washing and 24 hours post-chilling.

Beef carcass sampling and processing at the abattoir

Study 2: A total of 31 retail outlets including both large supermarket chains and smaller butcheries were randomly selected. Visits were made to each of these outlets during autumn, winter and summer months of 2016 for sample collection. Sampling of five types of popular beef products (brisket, boerewors, mince, cold meat, and biltong) was done at each outlet during each visit.

Each sample was analyzed for the presence of Shiga toxin-encoding genes (stx1and stx2) using conventional multiplex PCR. All samples positive for stx genes based on PCR were screened for the following O-serotypes: O26, O91, O103, O111, O113, O145 and O157 using a multiplex PCR assay.

Results and Discussion

Overall, the prevalence of STEC in beef carcass swabs collected from 12 red meat abattoirs across Gauteng province during summer and winter months was 35.5% (94/265). The highest prevalence (50%) was detected in perineal samples, which is hardly a surprise because cattle are an established reservoir of STEC; this may therefore reflect the prevalence of the pathogen in cattle arriving at abattoirs. Transportation stress is known to increase the shedding of enteric pathogens and could therefore be a contributing factor to the observed high prevalence in perineal samples. STEC was found in 39% of both pre-evisceration and post-evisceration carcasses, while washed carcasses and 24 hour chilled carcasses had a lower prevalence of 23% and 20% respectively. Therefore, although washing of carcasses at the abattoir removed much of the STEC contamination, the fact that the bacteria were still present on the surface of some chilled carcasses is of potential food safety significance, since cuts from these carcasses end up for sale in various forms at retail outlets.

Boerewors on display in a retail outlet

Of the 399 beef products sampled from 31 retail outlets, 67 (16.8%) were contaminated by STEC strains, an observation that is of food safety significance if such products were to be improperly cooked and consumed by highly susceptible individuals.

The highest prevalence of STEC was detected in boerewors (35%), followed by minced meat (21%). Ground beef ordinarily includes meat from many carcasses; consequently a few infected livestock could potentially contaminate a great quantity of ground beef. Biltong had the lowest prevalence of contamination (5%), while brisket and cold meat had 11% and 6% respectively. These results are in contrast to a previous study in South Africa, in 2009, involving biltong, cold meat and minced meat at retail outlets, which found that 2.8% of the samples were positive for E. coli O157 (1).

The prevalence of STEC in abattoir and retail outlet samples was somewhat higher during the summer months compared to the winter months. While many factors are believed to affect the prevalence of E. coli O157:H7, only season has been consistently shown to impact the shedding of this bacterium by cattle (2), and some previous studies have also observed a higher prevalence of shedding during the warmer months than the winter months.

The serotype analysis showed that O113 was the post prevalent serotype both on beef carcasses (14%) as well as in beef-based products (19%). This observation is of particular interest considering that O113 is an emerging serotype associated with human illness and sometimes with HUS in several countries including Spain, Belgium and Australia. Serotype O113 of STEC may therefore potentially be important in human diseases in South Africa and this requires further studies. Some of the other serotypes detected  have also previously been implicated in human diseases elsewhere in the world.

Unlike in abattoir samples where the prevalence of serotype O157 was very low (1%), a higher prevalence of 15% was detected in retail meat samples. This finding may be explained in part by the fact that the current study was cross-sectional by design (giving a “snapshot” at a particular point in time) and not a longitudinal study. Therefore serotype O157-contaminated beef products may have originated from abattoirs not sampled in the current study, and the prevalence may vary greatly between places and over time. There is also a possibility that it may partially also be a result of contamination from other sources at the retail outlet level.

Mince meat on display in a retail outlet


This study has shown that contamination of beef products with potentially harmful bacteria can occur during different processing stages. The low numbers of reported cases of food-associated disease in South Africa suggest that the risk to consumers is low; however, it is not known whether all cases are reported, or that all cases are correctly diagnosed. Therefore, further research is needed in order better understand the dynamics of foodborne pathogens in South Africa, to accurately assess the risk they pose, and to accurately inform control measures.

It is well known that efficient implementation of control measures during slaughter and processing procedures can greatly reduce meat surface microbial contamination and ensure the safety of the final product. The South African Meat Safety Act (2000) has addressed potential risk factors by adopting several internationally recognized preventive measures such as the Hazard Analysis Critical Control Point (HACCP) system and Good Manufacturing Practices (GMP) in order to promote safe meat for consumers. The application of GMP and HACCP principles during handling and processing of products, as well as the proper cooking of meat products before consumption, will effectively reduce the threat of food borne disease.


We thank Red Meat Research and Development South Africa (RMRD SA) for funding this research and the Gauteng Department of Agriculture and Rural Development for granting us access and assistance to carry out the cross-sectional survey at the abattoirs.


  1. Abong’o, B.O. and Momba, M.N., 2009. Prevalence and characterization of Escherichia coli O157: H7 isolates from meat and meat products sold in Amathole District, Eastern Cape Province of South Africa. Food Microbiology, 26(2), pp.173-176.
  2. Berry, E.D. and Wells, J.E., 2010. Escherichia coli O157: H7: recent advances in research on occurrence, transmission, and control in cattle and the production environment. Advances in Food and Nutrition Research, 60, pp.67-117.
  3. Browning, N.G., Botha, J.R., Sacho, H. and Moore, P.J., 1990. Escherichia coli O157: H7 haemorrhagic colitis. Report of the first South African case. South African Journal of Surgery, 28(1), pp.28-29.
  4. Effler, E., Isaäcson, M., Arntzen, L., Heenan, R., Canter, P., Barrett, T., Lee, L., Mambo, C., Levine, W., Zaidi, A. and Griffin, P.M., 2001. Factors contributing to the emergence of Escherichia coli O157 in Africa. Emerging Infectious Diseases, 7(5), p.812.
  5. Galane, P.M. and Le Roux, M., 2001. Molecular epidemiology of Escherichia coli isolated from young South African children with diarrhoeal diseases. Journal of Health, Population and Nutrition, 19(1), pp.31-38.
  6. Kiibel, P.J., 1968. The haemolytic-uraemia syndrome: a survey in Southern Africa. South African Medical Journal, 42(27), pp.692-698.
  7. Mora, A., Herrera, A., López, C., Dahbi, G., Mamani, R., Pita, J.M., Alonso, M.P., Llovo, J., Bernárdez, M.I., Blanco, J.E. and Blanco, M., 2011. Characteristics of the Shiga-toxin-producing enteroaggregative Escherichia coli O104: H4 German outbreak strain and of STEC strains isolated in Spain. International Microbiology, 14(3), pp.121-141.
  8. WHO [World Health Organization], 2015. WHO estimates of the global burden of foodborne diseases. Available at

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Peter Thompson

Methane and nitrous oxide from beef cattle manure

Direct manure methane and nitrous oxide emissions from a commercial beef feedlot in South Africa.

Industry Sector: Cattle and Small Stock

Research focus area: Sustainable natural resource utilization

Research Institute: University of Pretoria

Researcher: Dr JL Linde du Toit

Title Initials Surname Highest Qualification
Prof WA van Niekerk PhD
Miss K Lynch BSc(Agric)
Dr L Stevens PhD

Year of completion : 2017

Aims of the project

  • To identify the on-farm manure management system employed in a typical commercial beef feedlot in South Africa
  • To determine the methane emissions from manure in a commercial beef feedlot
  • To determine the nitrous oxide emissions from manure in a commercial beef feedlot

Executive Summary

Methane and nitrous oxide emission from pen surfaces in a commercial beef feedlot in South Africa

Global warming has become a worldwide concern in recent years.  The release of Greenhouse gasses (GHGs) have brought about rapidly changing climate conditions the world over, GHGs produced by various industry sectors are being investigated, researched and laws put in place to limit the production of GHGs wherever possible.  This includes the agricultural sector where extensive animal husbandry has increased the global carbon footprint and environmental pollution.

The International Panel of Climate Control (2006) has three Tiers that estimates methane (CH4) values, one of the main GHGs, from the use of default values to the use of more complicated models and experimental data to improve the accuracy of reporting.  This study investigated the contribution of manure GHGs emissions to livestock emissions focussing on intensive beef feedlot manure emissions. At present in South Africa, these values are only roughly estimated and are only available on an IPCC Tier 2 level.  Gaseous emissions from livestock waste, specifically beef cattle waste, are affected by a variety of external factors (atmospheric temperature, humidity, soil conditions, ration consumption and manure management practices) as well as internal factors, (ration digestibility, nutrient absorption and gut health).

The objective of the study was to achieve an understanding of the gaseous emissions, specifically methane (CH4) and nitrous oxide (N2O), from beef cattle feedlot pen surfaces from a commercial beef feedlot in South Africa as influenced by diet and season, using the closed chamber method of gas collection over the three prominent seasons experienced in Mpumalanga, South Africa.  The sampling of these various factors would lead to more accurate reporting, conforming to Tier 3 methodology results.

Random pen surface and emissions samples were taken from three pens per each feedlot ration fed. The results indicated significant differences in soil/manure characteristics, but little effect on ultimate CH4 and N2O emissions from the pen surface were found across treatments. Similar results were observed for the rangeland manure analysed and manure emissions from manure management practices at the feedlot.  Ambient temperature had a tendency (p<0.10) to affect CH4 and N2O emissions with higher temperatures resulting in higher emissions but. Overall soil and manure characteristics were affected by diet treatments and seasonal variation.  It must be noted that the lack of significant differences in gas emissions in the present study could have been due to sampling error. The gas emissions observed did show a trend between treatment levels and manure management practices within the feedlot, with the effluent dams and manure piles recording the highest CH4 emissions over each of the measured seasons.  The CH4 emissions varied between seasons within the feedlot, rangeland and manure management practices, but a level of significance was never observed even though manure characteristics observed significant differences.  The N2O emissions observed no set trend between areas measured on the feedlot.  The varying values, and negative values obtained may indicate sample error, or a general uptake of N by soil or microorganisms (Chantigny et al., 2007; Li et al., 2011).

In conclusion, it was found that manure characteristics are affected by season and diet characteristics which tended to have an effect on the rate of CH4 and N2O emissions from the manure, although not significantly.

Popular Article

Feedlot greenhouse gas study analyses emissions from pen surfaces and manure management

By CJL du Toit

Researchers from the University of Pretoria spend time at a commercial beef feedlot in Mpumalanga, South Africa to gain a better understanding of the greenhouse gas emissions originating from feedlots pen surfaces and manure.

Why are GHG emissions important to agriculture?

In agriculture and livestock production systems the three main greenhouse gases (GHG) include methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2).  Greenhouse gases impact the environment through their ability to trap heat which depends on their capacity to absorb and re-emit infrared radiation and the atmospheric life time of the different gasses.  Increasing atmospheric concentrations of GHG caused by fossil fuel combustion, industrial activities, land use change and agricultural activities contributes to changes in global temperatures and rainfall patterns which could impact directly on agricultural and livestock production.

Accurate estimation of GHG from anthropogenic sources is an increasing concern given the current and potential future reporting requirements for GHG emissions.  Research measuring GHG emission fluxes from feedlot surfaces and manure management has been very limited and this was the first research project on the topic under South African conditions.

Livestock manure and GHG emissions

Livestock manure is a source of nutrients and can be used for various purposes including soil amendments to improve fertility and productivity and the generation of green energy.  The main GHG emitted by manure are CH4 and N2O. Methane is produced during anaerobic decomposition of organic matter and N2O is emitted during nitrification and de-nitrification processes. Feedlot manure GHG emissions is influenced by a variety of factors including manure management (pile, anaerobic lagoon, rangeland), manure application (fertilization of rangeland, composting, bio-fermentation), temperature, aeration, moisture and the sources of nutrients in the manure which is in part caused feed inefficiencies. Emission is also influenced by animal factors in the feedlot such as stocking density which will influence the amount of manure deposited, feed intake and digestibility, animal type and age.

What did the researchers do?

Following an extensive review of current literature on GHG emission flux quantification from pasture, cropping and livestock enterprises it was decided to adopt closed static chambers as the measurement methodology. The aim of the study was to determine the effect of feedlot ration and season on the GHG emissions from manure at different sites within in a commercial feedlot operation. Chamber bases were randomly installed at each manure management site (rangeland, pen surface, manure piles and water catchment lagoons) during each season. The seasons were classified as wet and hot (WH), dry and cold (DC) and dry and hot (DH).

Gas samples were drawn from the chambers during mid-day at four time intervals within a 40 min measuring period and analysed using a gas chromatograph to determine average CH4 and N2O fluxes.

What did the researchers learn?

The method employed resulted in large variation within results sets mainly due to difficulty in sealing the chambers bases especially in the pen surfaces which were extremely compacted. The random placement of chambers also caused variation in results as some chambers had a higher manure density and factors such as soil and manure moisture varied between different locations within each pen.  The results yielded an average pen surface manure CH4 emission factor of 449 g/head/year which was 50% lower compared to feedlot manure emission factors previously calculated of 870 g/head/year using IPCC (2006) based models.  The N2O emissions measured from pen surfaces (10.95 g/head/year) were much lower than previously calculated or reported emission factors in literature varying from 54.8 to 2555 g N2O/ head/year.  Within the whole manure management system on the feedlot CH4 emissions from the water catchment dams were the highest followed by manure piles, feedlot pen surfaces and manure deposited on rangeland.  Although no statistical differences were found between the different seasons the wet and hot season produced the highest overall CH4 emissions and the dry and cold season produced the highest N2O emission across all manure management sites.

Managing GHG emissions from manure

The mitigation of GHG emissions from manure management in livestock operations is the topic of many research projects globally. Identified mitigation strategies are already being used by producers but new techniques and fine-tuning of existing options will lead to new and improved alternatives which can be tailored to country or regions specific production systems. The mitigation of GHG emissions from livestock production systems can be complicated as a strategy that reduces one emission may increase the other. Manure emissions can be reduced through two main actions namely input (providing of organic matter e.g. feeds) and manure management.  Overfeeding of nutrients such as nitrogen (N) will result in an increase in the amount of N excreted in manure which will lead to increased N2O emissions. To reduce GHG emission from manure producers will have to use feeding regimes that will maximise feed efficiency and reduce nutrient wastage. The management of on-farm manure can also be tailored to reduce GHG emissions and the effect of production systems on the environment.  The time of manure application to soil and rangeland is important to reduce emissions. Producers should avoid spreading manure when soil is are wet as this will increase CH4 emissions and attempt to reduce the storage time of manure on the farm. The use of technologies such as covered lagoons, digesters, aeration of manure and composting has all been employed to reduce CH4 emissions from manure.

On-going research

There is a need to develop standardised research methodology protocols, for both on-farm and laboratory experiments, which will make it possible to compare mitigation strategies and research results between different studies. Researchers are also attempting to understand the interplay of CH4 and N2O as it seems that the processes that produce these GHG are related.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Linde du Toit on

Heartwater survey on changes and causes

A Survey of veterinary and farmer experiences and opinions on heartwater incidence, distribution and associated factors in domestic ruminants in South Africa

Industry Sector: Cattle and Small Stock

Research Focus Area: Animal Health and Welfare

Research Institute: Faculty of Veterinary Science, University of Pretoria Department of Production Animal Studies

Researcher: Prof     Gareth Bath     ECSRHM

Title Initials Surname Qualification
Dr D Coetzee BVSc
Dr T Brink BVSc
Dr R Leask M. Med. Vet
Prof G Fosgate PhD

Year of completion : 2017

Aims Of The Project

  • To establish the extent and incidence of HW by a structured questionnaire sent to farmers and veterinarians in heartwater areas

  • To establish changes that may have occurred in these areas

  • To identify possible reasons for the changes observed.

  • To make recommendations for further action

Executive Summary

The Questionnaire Survey achieved the aims set out for the project. Sample sizes, structure, demographics, geographic distribution and experience profiles of both Veterinary and Farmer groups were adequate for gathering useful data and for conclusions to be drawn.

There appears to be epidemiologically significant change in the spatial distribution of heartwater in many areas, with serious expansion in some, of up to 150 kilometres, and 48% of veterinarians and 42% of farmers reported seeing increases in the number of farms affected by heartwater. The disease is also increasing in incidence and severity judging by the number of cases seen, increases in occurrence observed and also some indication that there is an increased risk of heartwater in more months of the year than in the past.

Climate change as a causative factor, indicated by observations of increased average temperatures, milder frosts, less rain and shorter rainy seasons, was identified by the majority of farmers but not by as many veterinarians. Respondents in both groups considered vegetation change an important factor. Increasing wildlife, especially antelope, was seen as a major factor by most veterinarians and also many farmers. Both groups identified the movement of livestock and wildlife as an increasingly important factor that must be seen as of major concern for both industries since it leads to the avoidable spread of many diseases apart from heartwater. Movement controls must be reinstated and reinforced by vigorously enforced legislation.

The use of the heartwater ‘vaccine’ is either unchanged or in decline and is apparently causing an increasing reliance on dipping and block treatments. Farmers reported mainly an increase in tick control by dipping and rated this as a very important factor in the management of heartwater; the veterinarians rated it lower. Control achieved by routine, regular block treatments of entire flocks or herds was also seen as a major factor and as increasing in use for both respondent groups, each giving it a high ranking. Relying on intensive tick control and ongoing block treatments leads to loss of efficacy in key acaricides and antibiotics and has very serious implications and consequences for the control of many diseases and parasites of livestock. The lack of a commercially available, safe, effective, practical and affordable true vaccine for the protection of ruminant livestock against heartwater should be of the absolute highest concern and priority. After decades of trials, OVI researchers have developed a very promising candidate vaccine, yet its further development to the commercial stage appears not to be receiving the urgency and attention needed.

Diagnosis of heartwater in post mortem cases is accurate and reliable if backed by appropriate histopathological staining and examination, but far too few farmers have their suspicions confirmed by laboratory tests. This leads to a danger of widespread misdiagnosis and the disease being potentially either under- or over-diagnosed. The problem extends to clinical cases especially, where diagnosis rests mainly on a few ‘typical’ signs. The presence of atypical forms of heartwater further complicates the problem.

Popular Article

Is Heartwater spreading and becoming worse, and why?

A survey of farmers and veterinarians in heartwater-prone areas of South Africa indicates that the disease is expanding in geographic area and increasing in severity. What are the possible reasons for this, what has changed in these areas, and what should be done to limit the impact of a worsening situation? The Heartwater Survey was undertaken by staff of the Faculty of Veterinary Science at Onderstepoort, and generously funded by the financial subvention of RMRD – SA.

A representative sample of veterinarians and farmers with adequate experience in areas where heartwater is a problem agreed to take part in the survey. The survey took the form of a structured, measureable and analysable set of questions in a standard questionnaire. The questionnaire was designed to allow comparisons to be made between the two groups, who were for the most part asked the same or similar questions. The responses of these two groups gave an insight into the current heartwater situation as it is experienced by the farmers and veterinarians in the heartwater areas, and shed some light on the importance of factors believed to be involved in the expansion of areas affected by heartwater and in the changes of its severity.

It was deduced from the responses of both groups that the disease is expanding its range in many areas, and alarmingly so – by an average of perhaps 60km and as much as 150 kilometres in some regions. The reports by both vets and farmers indicated that an increasing number of farms are becoming affected by heartwater, confirming that the disease appears to be spreading. It was also evident that annual losses caused by heartwater can be very high on some farms unless the disease is suppressed by unsustainable practices like intensive dipping or repeated blocking of entire herds and flocks with tetracycline antibiotics. Both groups also reported that the number of cases of heartwater is rising.

Several factors that were thought to be responsible for these changes were identified by the two groups, although they did not always agree on the relative importance of these factors. Climate change, evidenced by higher than average temperatures, milder frosts, lower rainfall and shorter rainy seasons, was seen as a major causative factor by most farmers but considered to be of less significance by the veterinarians. Both groups saw a change in vegetation as an important factor but more so by the vets, who also rated the role of increased wildlife and the movement of antelope as a major factor, more so than the opinion of the farmers. The groups were, however, in agreement about the important role played by the movement of livestock in the potential to increase the areas affected by heartwater.

The survey revealed that the use of the heartwater “vaccine” was stagnant or in decline, which is not surprising in view of the many difficulties encountered in its use, the risks and dangers inherent to it, and the uncertainties around its efficacy. Unfortunately this reluctance to use the vaccine has evidently led to an increasing use of frequent, suppressive tick control or reliance on regular blocking treatments for heartwater for entire herds or flocks. Neither of these control measures are sustainable in the long run, and are almost certain to hasten the onset and rapid development of drug resistance in the bont tick and the heartwater organism. It was also clear from the survey that the diagnosis and treatment of heartwater relies far too heavily on the clinical signs or symptoms seen, especially with the farmers, leading to the dangers of misdiagnosis.

In conclusion, the survey revealed that heartwater is increasing in both its geographic extent and its severity, at least in some areas, and that a number of factors appear to be involved in causing these changes. Chief of these were climate, vegetation, and wildlife and livestock movements. The role of static or declining vaccine usage, leading to an increased reliance on intensive tick control, or alternately the widespread use of whole herd blocking with tetracycline antibiotics was also revealed by the responses of both groups.

The most pressing need now to bring about satisfactory heartwater control is the rapid and prioritised development of a commercial vaccine by OBP that is safe, effective, practical, easy to use and affordable. This development can be based on the very promising candidate vaccine developed by OVI. Ensuring that the movement of both wildlife and livestock is properly controlled to try to reduce the spread of the disease is another priority requiring urgent attention.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Gareth Bath on

Improved red meat marketing in South Africa

Improving the effectiveness of the red meat industry in meeting the needs of the modern consumer within South Africa as a developing country with socio-economic diversity

Industry Sector: Cattle and Small Stock

Research focus area: 

  • Red Meat Safety, Nutritional Value, Consumerism and Consumer Behaviour
  • The economics of red meat consumption and production in South Africa

Research Institute: Bureau for food and agricultural policy (BFAP)

Researcher: Mrs Hester Vermeulen

Research Team

Title Initials Surname Highest Qualification
Prof Ferdi Meyer PhD Agricultural Economics
Prof HC Schönfeldt PhD
Dr B Pretorius PhD

Completion: 2017

Aims of the project

  • Improving the effectiveness of the South African red meat industry in meeting the needs of the socio-economical diverse consumer market in South Africa through the development of scientifically based recommendations to guide policy development and product development / improvement.
  • To identify and characterize consumer market segments among low-, middle- and high LSM consumers in South Africa based on consumers red meat perceptions and behavior – considering a variety of species and meat cuts guided by data availability.
  • To develop scientifically based recommendations for the promotion of red meat in South Africa through appropriate marketing messages delivered through suitable communication channels to maintain and / or improve consumers’ perceptions and acceptance of red meat – considering a variety of species and meat cuts guided by data availability.
  • To engage in GAP analysis in order to identify the discrepancies between the actual current characteristics and ideal characteristics (demanded by consumers) of the red meat product offering on South African retail shelves – considering beef and mutton/lamb and a selection of fresh meat cuts guided by data availability.

Executive Summary

Meat purchasing and preparation behaviour:

  • Meat purchasing roles:
    • Marketing information on red meat should have a strong focus on adult women (‘wife’ or head female in households) as the primary red meat purchasers, but still keeping in mind that all age and genders groups within the household could influence her red meat purchase decision. Given the increased role of the husband / head male on meat purchasing during weekends and when selecting meat to entertain guests, red meat information related to these more social settings should be targeted at both male and female adults.
  • Factors considered when purchasing red meat:
    • Across the socio-economic spectrum, for both raw beef and raw mutton/lamb the following factors were important to consumers when making a purchase – and are thus important factors to focus on in terms of red meat production and marketing, no matter which socio-economics group is targeted:
      • Affordability: Price.
      • Appearance: General appearance, colour of meat, colour of fat.
      • Food safety: Food safety in general, expiry date, clean meat (no blood).
      • Quality: Quality guarantee, fresh, fresh not frozen.
      • Sensory acceptability: Tasty, tender, juicy, eaten by all in household.
      • Convenience: Convenience in general, preparation time.
      • Fat: Fat-to-meat ratio, low fat / lean meat.
      • Store where meat is purchased.
    • Among the low-income sample value-for-money considerations such as bone-to-meat ratio, amount of meat per packet and packaging size were also important. The importance of branding and nutritional value increased towards the middle- and high-income samples.
  • Meal planning:
    • As consumers across the socio-economic spectrum usually choose the meat for the meal first and then the other dishes it is critical to ensure that red meat is positioned as a popular ‘spontaneous’ choice in consumers’ minds.
    • Consumer education on red meat meal preparation ideas should rely on multiple sources with the dominant sources being ‘social’ sources and radio for the low-income sample, and recipes, ‘social’ sources (such as friends, mother), television and magazines for the middle- and high-income samples.
  • Red meat preparation and cooking:
    • For beef the most popular cooking methods were stewing, frying and braai. For the low-income group stove-top boiling was also prominent, while roasting and grilling popular cooking methods among middle-income and high-income consumers.
    • When preparing mutton/lamb low-income consumers used frying, boiling and braai, while middle-income consumers mainly used casserole, potjie, braai, roasting and stewing (in order of importance). High income consumers used stewing, braai, roasting, frying and grilling (in order of importance) for lamb/mutton.
    • Among middle- and high-income consumers the time allocated to meat preparation increased during weekends and even more so when entertaining guests. Thus, when targeting these segments with meat preparation information and recipes for more ‘social’ meals, more complex and longer preparation time can be used. However, during the week these consumers want meat options that are easy and fast to prepare.

Meat consumption behaviour:

  • Perceived importance of protein food intake:
    • Considering the statement: ‘It is important to eat animal protein foods daily’, the majority of high- and middle-income consumers were in agreement (96% of high-income sample versus 86% of middle-income sample).
    • Considering the statement: ‘It is important to eat red meat 3 to 4 times per week’, a smaller share of high- and middle-income consumers were in agreement (65% of high-income sample versus 39% of middle-income sample).
    • There seems to be a gap for consumer education particularly among middle- and high-income consumers on the recommended healthy intake of red meat and the health benefits associated with red meat.
  • Protein food intake:
    • The animal protein food options consumed in largest quantities were (in order of importance):
      • Low-income consumers: Chicken, eggs, beef, chicken offal, fish and beef.
      • Middle-income consumers: Chicken, eggs, fish and beef.
      • High-income consumers: Chicken, beef, eggs and fish.
    • The most frequently consumed animal protein food options were (in order of importance):
      • Low-income consumers: Eggs, chicken offal, chicken meat, canned fish, polony / viennas, boerewors, beef liver and stewing beef with bone.
      • Middle-income consumers: Chicken, eggs, beef mince, fish, boerewors, beef (stewing, steak, roast, sausage), cold meats, mutton/lamb (chops, stew).
      • High-income consumers: Chicken, eggs, beef (mince, stew, steak, sausage), cold meats, pork, fish, mutton/lamb.
    • The results in terms of the most popular meat option and red meat cuts could provide the red meat industry with important market intelligence in terms of actions to ensure the continued popularity of prominent cuts as well as the identification of ‘underutilised’ cuts. Furthermore, the meat intake data presented in this report could be very valuable from a food intake / nutritional / food security perspective, as it provides more detailed information on the meat consumption patterns of South African consumers.
  • Changes in red meat intake over time:
    • A significantly larger share of the low-, middle- and high-income consumers indicated that they consumed less red meat than 2 years before the survey (Beef: 87% of low-income consumers, 75% of middle-income consumers and 80% of high-income consumers; Mutton/lamb: 72% of low-income consumers, 85% of middle-income consumers and 88% of high-income consumers). These shares are significantly higher than previous research (2003) where 45% of the total sample reported reduced beef intake. Red meat was mainly replaced by chicken meat and some fish. The main reasons for reduced red meat intake (similar to past studies) were high prices (expensive) and some health concerns.
  • Popularity of red meat among household members:
    • Red meat was generally more popular among adult consumers than among children and teenagers. There might be a growth opportunity for the red meat industry if red meat could be made more appealing to younger consumers, e.g. through innovative product formats, child-friendly recipes and consumer health education.

Meat perceptions:

  • About a third of the low-income consumers remove all visible fat before cooking, while about 15% remove some visible fat before cooking beef and chicken. The serving of meat ‘pan drippings’ originating from the cooked meat applied to about half of the low-income consumers.

Red meat safety:

  • When defining red meat safety consumers across the socio-economic spectrum focused on clean meat, clean purchase environment, meat colour, freshness, grading, expiry date, healthiness and good quality.
  • Considering the relationship between red meat quality and red meat safety a large share of respondents perceived the terms to the basically the same and being equally important when purchasing red meat.
  • The large majority of all respondents (78% to 98% of the various socio-economic sub-samples) perceived food safety as an important factor considered when purchasing red meat. However, only about 13% of the low-income consumers and about a third of the middle- and high-income consumers had red meat safety concerns. It could be argued that consumers ‘control’ for food safety by carefully selecting their red meat purchase outlets. It is also important to note that food safety seems to be a ‘non-negotiable’ attribute to consumers – it has to be in place, implying a responsibility on the red meat industry and retailers to ensure the safety of red meat sold to South African consumers.
  • The low- and middle-income consumers were most concerned about the safety of beef, followed by chicken, while the high-income consumers were most concerned about safety of chicken and beef.
  • The most trusted purchase outlets for red meat are dominated by specific trusted butchery shops and formal major retail chain store, while the most risky purchase outlets for red meat are dominated by hawkers / street vendors, spaza shops, small independent retailers, certain butchery shops and certain chain retailers.


  • The purchasing frequency of take-away meals differed significantly between income groups, with weekly take-away food purchasing observed for 5% of low-income consumers, 19% of middle-income consumers and 29% of high-income consumers. The results confirmed the dominance of chicken as a popular meat choice among all socio-economic groups, even though beef is also a prominent choice among high-income consumers when purchasing take-away meals.
  • The purchasing frequency of restaurant meals differed significantly between income groups, with weekly restaurant food purchasing observed for 6% of low-income consumers, 11% of middle-income consumers and 9% of high-income consumers. In terms of meat types chicken is the dominant option purchased from restaurants by the middle-income group, even though the popularity gap between chicken and beef is less prominent than for take-away meals. Among the high-income sample beef is the most popular option, followed by fish/seafood.
  • Challenges facing the red meat industry includes increasing the appeal of beef within take-away- and restaurant meals, particularly among the middle-income group; and increasing the appeal of mutton/lamb within restaurant meals, among middle- and high-income consumers.

Red meat information sources:

  • The most highly used and trusted red meat information sources for the particular socio-economic sub-segment were the following:
  • Low-income consumers: TV, radio, advertising, doctors, newspapers;
  • Middle-income consumers: TV, family, friends, doctors, recipe books, radio, food labels;
  • High-income consumers: Family, friends, food labels, recipe books, butcheries, doctors, dieticians.
  • Doctors are among top 10 most used and most trusted meat info sources for all income sub-segments;
  • TV and radio are the top 10 most used and most trusted meat info sources for middle income and low income sub-segments. However, the particular channels / stations will vary between LSM groups.
  • Family and friends (possibly linked with social media), recipe books and food labels are among the top 10 most used and most trusted meat info sources for middle income and high income sub-segments.
  • Advertising and newspapers are among the top 10 most used and most trusted meat info sources for low income sub-segment only, while butcheries and dieticians among top 10 most used and most trusted meat info sources for high income sub-segment only.

Red meat classification:

  • Among low LSM consumers there is a very limited understanding and attention given to red meat classification. Even though middle LSM and high LSM consumers also have a limited understanding of red meat classification, around half of these sampled consumers check the grading / classification mark sometimes or often when buying beef or mutton/lamb.
  • The association of red meat classification with meat quality and safety was limited. Even though many respondents did not mention red meat classification / grading directly when defining red meat quality and safety, many aspects related to it was mentioned such as freshness, meat colour, appearance, smell, tenderness, taste and leanness.
  • Among an extensive range of red meat decision factors ‘grading / classification’ was not among the top 20 most important factors. However, many aspects related to red meat grading / classification was important such as appearance, taste, flavour, quality guarantee, meat colour, fat content, juiciness and tenderness.
  • It is interesting to note that the results presented on the radar plots in terms of consumers’ red meat decision factors, the place of purchase is a stronger quality cue to consumers than the certification marks on the meat. This is an important observation and should be further investigated.

Credence / intangible red meat attributes:

  • The most popular intangible attributes among the middle-income consumers were (in order of importance) (% of sample perceiving attribute as ‘very important’ indicated in brackets): environmentally friendly production (54%), free range (49%), no growth hormones given to animals (44%), animal friendly production (44%), breed of animal (43%) and no GM feed given to animals (43%). The question however arises whether these consumers have the purchasing power to afford the price premiums associated with these attributes.
  • The most popular intangible attributes among the high-income consumers were (in order of importance) (% of sample perceiving attribute as ‘very important’ indicated in brackets): no growth hormones given to animals (56%), no GM feed given to animals (49%), environmentally friendly production (48%), animal friendly production (39%) and free range (36%).
  • In terms of demographic variables (LSM group, gender, age, ethnicity, marital status, household income level and education level), within the middle- and high-income samples, the segments deeming intangible attributes as ‘very important’ did not differ significantly from the alternative segments.
  • The most highly used and highly trusted red meat information sources among the middle- and high-income consumer samples for consumers who perceived at least four or more of the intangible attributes as ‘very important’ were TV, family friends, advertising, food labels, recipe books, newspapers, butchers, radio, magazines, retailers, dieticians, food industry, public health recommendations, doctors, farmers and consumer organisations. These results (presented for each intangible attribute separate in the particular chapter) present marketers of red meat with a valuable overview of the marketing channels to use when marketing red meat products with particular intangible product traits.

Market segmentation for specific beef and mutton/lamb cuts:

  • Market segmentation for individual red meat cuts were based on respondents’ consumption frequency for the various cuts, considered at four consumption frequency levels: weekly (‘weeklies’), 1 to 3 times per month (‘monthlies’), occasionally (‘occasionals’) and never (‘non-users’).
  • Among the low-income consumers the most popular red meat cuts (with the highest shares of ‘Weeklies’ and ‘Monthlies’ combined) were: offal in general (78.8%), beef stew (67.1%), beef mince (46.7%) and beef steak (43.0%). Offal was significantly more important among the low-income sample compared to the wealthier samples.
  • Among the middle-income consumers the most popular red meat cuts (with the highest shares of ‘Weeklies’ and ‘Monthlies’ combined) were: beef mince (89.6%), beef stew (84.2%), beef steak (59.1%), beef roast (48.5%), mutton/lamb chops (39.7%), offal in general (32.8%) and mutton/lamb roast (31.6%).
  • Among the high-income consumers the most popular red meat cuts (with the highest shares of ‘Weeklies’ and ‘Monthlies’ combined) were: beef mince (95.1%), beef stew (83.8%), beef steak (79.9%), mutton/lamb chops (69.4%), beef roast (60.5%), mutton/lamb stew (56.0%) and mutton/lamb roast (28.7%).
  • In terms of demographic variables the results indicated that consumers’ consumption frequency of red meat cuts did not generally differ in terms of household’s size and income as well as the respondent’s gender, age and ethnic group. However, the more aggregated wealth level of consumers (in other words whether they were among the low-, middle- or high-income samples) did make a differences in terms of their red meat intake frequency – with more frequent intake generally associated with higher income brackets.
  • In terms of typical weekly expenditure on particular red meat cuts, more regular low-income consumers revealed a tendency to spend more on red meat considering the segments for beef mince and beef steak. More regular middle-income consumers revealed a tendency to spend more on beef mince, beef steak, beef stew, beef roast, mutton/lamb chops and mutton/lamb roast.
  • In terms of typical quantity of raw red meat consumed per week, more regular middle-income consumers revealed a tendency to consume a larger weekly quantity of beef mince, mutton/lamb chops, mutton/lamb roast, mutton/lamb stew. More regular low-income consumer revealed a tendency to consume a larger weekly quantity of beef offal and mutton/lamb offal. The lack of significant differences for the other cuts within the three main samples once again imply that since more regular consumers and less regular consumers of red meat consume a similar quantity of red meat per week, the more regular segments could be consuming smaller quantities per (more regular) eating occasion.
  • For the various red meat cuts, considered for the low-, middle- and high-income samples, this section also presented information on consumers’ perceptions regarding beef and mutton/lamb, purchase factors, and best information sources to use to provide consumers with red meat information.
  • Across red meat cuts and socio-economic samples, consumers were very consistent in terms of their requirements for red meat labels, with preferences for detailed information and reliable information, date information (use-by date, sell-by date, last day of processing) and information pertaining to production processes (particularly in terms of the use of antibiotics / hormones and also free range in some cases).

Red meat labelling – What do consumers want and what do they see on labels?

  • The red meat labelling aspects that are highly desired by consumers and were widely observed on fresh red meat labels were: price, quality guaranteed, sell-by date and brand.
  • Despite being very important to consumers, labelling information relating to fat content, nutritional value and classification were not commonly observed on the fresh red meat labels.
  • In terms of date information packaging date, sell-by date and expiry date were the most commonly found on fresh red meat labels.


Red meat consumer education – key messages and marketing channels focusing on beef

Mrs Hester Vermeulen, Bureau for Food and Agricultural Policy

Prof Hettie Schönfeldt, University of Pretoria

Dr Beulah Pretorius, University of Pretoria

 Acknowledgements: Project funding provided by Red Meat Research and Development SA (RMRD-SA)


‘Background’ pictures /photos of the following could work well with this article:

  • Consumer buying beef in a shop
  • Consumer preparing beef in kitchen
  • Eating beef in a restaurant
  • Braai with beef on the grid
  • Example of a nutritional label from a beef product


The share of South African adults within the various socio-economic sub-groups changed significantly from 2005 to 2015, with the marginalised consumers decreasing by 52%, the middle class increasing by 50% and the more affluent consumer group increasing by 32%. The future of the South African red meat industry relies on an industry that are profitable and able to adapt to changes in consumer demand, the production environment and sustainability.

In 2012 the South African red meat industry commissioned a comprehensive consumer study to investigate the red meat behaviour and perceptions of the South African low-, middle- and high-income consumers in Gauteng amongst 586 consumers. The study sample was designed to reflect the income, ethnic and age groups of the South African population. The focus of this article is specifically on the identification of key marketing messages and marketing channels for red meat marketing.

How do South African consumers perceive beef?

Respondents were asked to indicate their level of agreement with a series of statements involving potential attributes of beef, pertaining to health / nutrition, affordability, product usage, product procurement, preparation, sensory quality and potential negative aspects.

Considering the positive perceptions of consumers regarding beef, there is significant overlap between income groups involving the following:

  • Product procurement: Beef is easy to obtain.
  • Product usage: Consumers know how to prepare beef, it is easy to cook the meat, it is versatile, good for entertaining and ideal for braai.
  • Sensory quality: Beef is tasty and tender and it does not smell bad.
  • Health / nutrition: Beef is a source of good quality protein and iron, it is nutritious and helps the body grow.
  • Product origin: Beef is locally produced and not imported.

The aspects which dominated the ‘positive’ set for beef of all income groups were: versatile, tasty, know how to prepare it, easy to obtain, good for entertaining, easy to cook and good quality protein source. Popularity when eating in a restaurant was also applicable to the middle-class and more affluent group, with higher importance in the latter group. Furthermore the more affluent group was also positive about further health / nutrition aspects (such as ‘healthy’ and ‘contains iron’), shelf life at home (‘does not go off fast’) and affordability (‘value for money’ and ‘not a luxury’).

Among marginalised and middle-class groups the major concerns (i.e. negative perceptions) focused on beef being expensive, having long cooking times and could cause health problems. Among the more affluent consumers the major beef concerns focused on specific health aspects (high in cholesterol, could cause health problems, can make me ill) and long cooking times required. A significantly larger share of the low-income sample was negative towards beef in terms of the following beef aspects: expensive, long cooking times required, can make me ill, high in fat and ‘not good for the heart’. In general a higher share of the marginalised group was in agreement with these negative aspects pertaining to beef, in contrast to a lower share of the more affluent consumers. As would be expected, consumers’ concerns regarding the affordability of beef decreased as income levels increased.

How do these perceptions translate into marketing messages to promote SA beef?

To enhance beef consumption in the South African context key marketing messages needs to take these observed perceptions into account. Beef product attributes and perceptions and translated marketing messages are proposed in

Table 1.

Product usage and preparation:

Across the socio-economic spectrum consumers were very positive about beef being versatile, easy to cook, knowing how to prepare it, good for entertaining and ideal for braai. The industry could invest or continue to invest in product- and recipe development to ensure that beef remains versatile, familiar, easy-to-cook, ‘trendy’ and a number one choice when entertaining of having a braai. Innovative ways to reduce beef cooking time for consumers with limited time should also be investigated, as well as innovative and tasty recipes to ‘stretch’ beef in dishes. However, it is important to consider the varying life styles, preferences and budgets of the socio-economic sub-groups in the process.

Sensory appeal:

All consumer segments were very positive about beef being tasty and not smelling bad. The middle-class was more positive about the tenderness of beef, even though tenderness was among the positive perceptions of all sub-groups. Sensory appeal is a critical product attribute for beef, even more so given its price premium about chicken meat. Production and product handling practices should continuously be improved, based on sound scientific research, to ensure ‘better beef’ – satisfying the sensory enjoyment needs of consumers of all income groups (e.g. in terms of taste, tenderness, smell and visual appeal).

Health – food safety:

Only the more affluent group was very positive about beef not spoiling fast at home. The lack of cold-storage facilities in the homes of lower-income consumers could contribute to this observation. However, there seems to be a need for consumer education on safe meat handling practices, particularly among the marginalised and middle-class groups.

Health – nutritional value:

All consumers perceived beef as being nutritious, a good quality protein source, helps the body grow and being a source of iron. Only the more affluent group were very positive about beef being ‘healthy’. The research results suggest that consumers (across the socio-economic spectrum) need to be educated on the nutritional value of beef, pertaining to various aspects such as macro-nutrients (i.e. protein, fat) and micro-nutrients (i.e. vitamins and minerals). However, it should be kept in mind that the complexity of nutritional information communicated to consumers should be tailored to their typical educations levels.

Health – fat & cholesterol:

Over the last decade or two a growing body of scientific publications confirm the trend of consumers moving towards leaner red meat cuts. In this study consumers were concerned about beef in terms of fattiness, being high in cholesterol and the intake of beef linked to heart disease – with the marginalised group being particularly negative. Addressing consumers’ red meat fattiness concerns is critical, even more so in the light of the rising prevalence of overweight and obesity in South Africa. Corrective actions could include the following:

  • Presenting consumers with leaner beef cuts (e.g. through animal production processes and / or trimming of fat from beef cuts before sale).
  • Consumer education on the tasty preparation of leaner beef cuts (including aspects such as fat trimming at home and avoiding excessive fat intake through actions such as serving pan-drippings with meat with a high fat content).
  • Presenting consumers with a balanced and scientifically sound view on issues pertaining to beef fattiness, cholesterol and heart disease.

Product origin:

All consumers were positive that the beef they buy is usually local meat, suggesting some loyalty to locally produced beef. This is even more important if the large quantity of chicken being imported into the country is considered. The industry could do much more to communicate the origin of beef to consumers and extract some value from consumers’ loyalty towards locally produced meat.

Table 1: Proposed key marketing messages translated from consumers’ perceptions regarding beef meat

Product attributes and perceptions Key marketing strategies and messages
Product usage and preparation:
•     Versatile

•     Easy to cook

•     Knowing how to prepare

•     Good for entertaining

•     Ideal for braai

ü Continuous product- and recipe development to ensure that beef remains versatile, familiar, easy-to-cook, ‘trendy’ and a number one choice when entertaining or having a braai

ü Tasty recipes to ‘stretch’ beef in dishes

ü Innovative ways to reduce beef cooking time

Sensory appeal:
•     Beef is tasty

•     Beef is tender

•     Does not smell bad

ü Improved production and product handling practices based on sound scientific research, to ensure ‘better beef’
Health – food safety:
•     Beef do / does not spoil fast ü Consumer education on safe meat handling practices
Health – nutritional value:
•     Beef is nutritious

•     Beef is a good quality protein source

•     Beef helps the body grow

•     Beef is a source of iron

•     Beef is too fatty

•     Beef is high in cholesterol

•     Eating beef causes heart disease

ü Consumer relevant education on the nutritional value of beef, pertaining to various aspects such as macro-nutrients (i.e. protein, fat) and micro-nutrients (i.e. vitamins and minerals).

ü Leaner beef cuts

ü Consumer education on the tasty preparation of leaner beef cuts

ü Presenting consumers with balanced and scientifically sound messages on issues pertaining to beef fattiness, cholesterol and heart disease

Product origin & Affordability:
•     Beef is locally produced

•     Expensive

ü Communicate the origin of beef to consumers

ü Address affordability issues through promoting it as an ‘essential luxury’ or by providing more affordable meat cuts to the consumer

Which communication channels are most suitable to communicate these marketing messages to SA consumers?

Being presented with a list of potential red meat information sources, consumers were asked to evaluate the usage and trust of these sources. Table 2 summarised the most used and trusted information sources amongst the different consumer groups to use in marketing strategies. However, given the diversity of the market the specific channels (e.g. which television channels or which newspapers) as well as the complexity of marketing messages has to be tailored to the behaviour and education levels of the targeted consumers.

Table 2: Highly used and highly trusted red meat information sources (Source: Survey data) 

Category: Information source: Marginalised




More affluent


Printed information sources: Magazines




ü û
Recipe books


Food labels




ü ü
Medical information sources: Doctors




û ü ü
Retail information sources: Retail stores


ü ü û


ü ü
Social information sources: Family




Broadcasting information sources: Television




Other information sources: Public health recommendations


ü ü ü
The food industry


û û ü

(NOTES: : Indicates red meat information sources that dominates for the particular sub-group)

Conclusions and implications

Red meat consumption lags behind white meat consumption in South Africa and is losing ground steadily. Marketing efforts to stimulate the consumption of red meat among consumers should build upon aspect where consumers are already positive about beef such as: versatility, know how to prepare, good for entertaining, taste and nutrition (a nutritious meat and a good quality protein source). Furthermore the negative perceptions (affordability, fat and cholesterol content, long cooking time and could be a cause of health problems) should be improved.

Given the dynamic nature of the South African consumer environment with constant socio-economic changes and the influence of global consumer trends, the preferences and behaviour of South African consumers have a very dynamic nature. Subsequently it could be particularly valuable for the South African red meat industry to engage in follow-up surveys of this nature every few years in order to keep track of these dynamic changes.

Please contact the Primary Researcher on the project if you need a copy of the comprehensive report – Hester Vermeulen on

Amino acid composition of South African beef

Determining the amino acid profile of selected cuts from four age groups of South African beef, as additional to the previously approved project on the nutrient content of South African beef, in order to determine protein quality.

Industry Sector: Cattle and Small Stock

Research focus area: Red Meat Safety, Nutritional Value, Consumerism and Consumer Behaviour

Research Institute: Animal and Wildlife Science, University of Pretoria

Researcher: Prof Hettie Schönfeldt PhD

Team members

Title Initials Surname Qualification
Dr N. Hall Ph.D
Dr B. Pretorius Ph.D

Year of completion : 2017

Aims Of The Project

  • To determine the amino acid profile of South African beef
  • To determine the validity of using nitrogen and a specific Jones factor to define protein quantity
  • To determine the protein quality of South African beef in the context of human nutrition

Executive Summary

Globally protein quality is under the spotlight. The importance of protein quality was emphasized by both the 2007 and the 2011 Food and Agriculture Organization/ World Health Organization (FAO/WHO) Protein and amino acid requirements in human nutrition reports. These reports questioned the validity of current measures to determine crude protein content and protein absorption, and called for more research. Locally, the national Department of Health Directorate Food Control’s most recent legislation on food labelling and advertising requires that in order to make protein content claims, amino acid data in addition to crude protein (nitrogen), is needed.

During this project, raw and cooked beef cuts (prime rib, rump and shoulder) from all four age groups according to the South African classification system were sent for amino acid analyses at the ARC Irene Analytical laboratory.

Aligning with international debates, a literature review was completed to investigate existing literature on the validity of using the Jones factor of 6.25 to quantify the amount of protein from nitrogen within the red meat matrix. Amino acid data obtained was also compared to the use of the Jones factor to quantify the total protein content of red meat, and alternative factors were explored – similar to what has been done by Sosulki et al. in 1990. Mariotti et al (2008) also queried the use of 6.25 as the converting factor for red meat. Our study found that complete amino acid profiles of local beef amounted to 91% on average of protein based on total Nitrogen content (in weight). This indicates that there is an overestimation of protein in beef when the conversion factor of 6.25is used.

For local legislative purposes, the study found that all cuts from all age groups contain adequate quantities of the essential amino acids as required by the R.429 Food Labelling Legislation. This provides the scientific evidence required for South African beef to make protein content and functional protein claims on packaging and in marketing activities.

Technology transfers

  1. Participation of the Human Nutrition and Health Committee Meeting of the International Meat Secretariat (Canada, 1-3 July, 2015) (Addendum 2)
  2. Participation of the Human Nutrition and Health Committee Meeting of the International Meat Secretariat (Oslo, Norway, 15-18 July, 2016) (Addendum 2)

Reports to Industry

  1. NRF-THRIP progress report 2014
  2. NRF-THRIP final report 2015
  3. RMRD SA Progress report 2014
  4. RMRD SA Progress report 2015

Scientific articles

  1. Schönfeldt H.C., Pretorius B. and Hall, N. (2016) ‘Bioavailability of Nutrients’, In: Caballero, B., Finglas, P., and Toldrá, F. (eds.) The Encyclopedia of Food and Health vol. 1, pp. 401-406. Oxford: Academic Press.
  2. Article to be submitted after presenting “Updating and expanding the Food Composition Table for Western Africa“ at International Food Data Conferences (IFDC) – Official INFOODS conference. Center for Science in the Science and Technology Pole, Buenos Aires, Argentina. 11-13 October 2017.
  3. Article to be submitted after presenting “Amino acid and protein content of lean beef“ at International Food Data Conferences (IFDC) – Official INFOODS conference. Center for Science in the Science and Technology Pole, Buenos Aires, Argentina. 11-13 October 2017.


  1. Hall, N. 2015. Sustainable red meat from a nutrition perspective. University of Pretoria.

Conferences, symposia

  1. Co-author FAO/INFOODS (2017) Updating and expanding the Food Composition Table for Western Africa. 12th International Food Data Conference (IFDC) – Official INFOODS conference.
    Center for Science in the Science and Technology Pole, Buenos Aires, Argentina. 11-13 October 2017.
  2. Schönfeldt, H.C., Hall, N., Pretorius, B. and Van Deventer, M.M. (2017) Amino acid and protein content of lean beef. 12th International Food Data Conference (IFDC) – Official INFOODS conference. Center for Science in the Science and Technology Pole, Buenos Aires, Argentina. 11-13 October 2017.

Literature review

  1. Hall, N.G. and Schönfeldt, H.C. (2013) ‘Total nitrogen vs amino-acid profile as indicator of protein content of beef’, Food Chemistry. 140 (3): 608-612.

Popular Article

Globally protein quality is under the spotlight

Hettie Schönfeldt, Beulah Pretorius, Nicolette Hall, Maricia van Deventer

Department of Animal and Wildlife Sciences, Institute of Food, Nutrition and Well-being, University of Pretoria.

There has been much discussion regarding protein and amino acid requirements for both adults and children over the past few years.

Conventionally, protein content is determined by analysing the total nitrogen content in a food, and multiplying this by a standard conversion factor to obtain protein quantity – referred to as “crude protein”. Because proteins are made up of chains of amino acids, they can be hydrolysed and the separate amino acids can then be measured. The sum of the amino acids then represents the protein content (by weight) of the food. This is sometimes referred to as a “true protein”. This method however needs sophisticated equipment and is more expensive.

A project at the University of Pretoria aimed to determine the protein content and amino acid profile of South African beef (raw and cooked) and to establish if different cuts in the carcass and/or age of the animal influences the amino acid profile of South African beef.

Crude protein and amino acid analyses were done on 36 meat samples from Bonsmara carcasses from fat code two and all four age groups according to the South African Carcass Classification System. Three cuts (rump, prime rib and shoulder) were selected from each carcass and analyses were done on both raw and cooked meat.

Age had no significant effect on the sum of all amino acids (true protein) in both raw and cooked cuts. In the cooked cuts crude protein were found to be significantly different between the age groups for the different cuts. It should however be noted that these differences, although statistically significant, probably have little relevance in terms of human dietary requirements for protein as they differ by less than 2 g per 100 g cooked meat.

The data generated by this study is of further interest as discussions regarding the validity of nitrogen analyses for protein quantity determination and methods used to assess protein quality unfold. Table 1 shows the percentage of total amino acids to protein calculated with the Jones factor. It would be more appropriate to base estimates of protein on amino acid data.

Table 1: Percentage of sum of amino acids (‘true protein’) to protein calculated from total nitrogen using the Jones-factor (‘crude protein’)

Cut Raw / Cooked Percentage (Sum of amino acids / protein calculated from total nitrogen x 100)
Rump Raw 95%
Cooked 89%
Prime rib Raw 97%
Cooked 90%
Shoulder Raw 94%
Cooked 89%

Instead of simply focussing on total protein, attention has shifted to the greater importance of protein quality than actual quantity, emphasising the presence of individual amino acids in a food. One method of measuring protein quality is determining the quantity of the total essential amino acids and the digestibility of the protein source (PDCAAS). Data on the amino acid composition of foods is therefore essential in order to contribute to the current global discussion.

Protein quality answers two important questions namely, how much protein as well as what kind of protein should be consumed. Dietary proteins are classified as either being complete or incomplete. Some foods, such as animal source food, contain all indispensable (essential) amino acids and are referred to as a complete protein. Plant foods, on the other hand, lack one or more essential amino acid, which renders these sources of protein “incomplete”. Amino acids containing sulfur (including methionine and cysteine) and lysine most commonly limit the nutritional value (quality) of proteins in the human diet. Concentrations of these amino acids are, generally, considered lower in plant foods than in food of animal origin. In table 2 the lysine, methionine and cysteine content of commonly consumed food products is reported. Other essential amino acids, lysine and tryptophan, are also consistently found at lower concentrations in plant-based rather than animal-based foods. For example, tryptophan and lysine are limiting in corn; lysine in wheat, sorghum, and other cereals; and methionine in soybeans and other legumes. Including a small amount of lean beef in combination with plant-based foods can increase the protein quality of the meal.

Table 2: Lysine, methionine and cysteine content of commonly consumed food products

Food source  Food Range (mg/100g) from different studies
Lysine Methionine Cysteine
Animal products Beef and Veal (edible flesh) 531–591 147–182 78–182
Chicken (edible flesh) 384–606 88–215 64–114
Offal 375–506 138–181 62–132
Mutton and lamb (edible flesh) 438–589 131–198 63–144
Hen eggs 375–467 181–249 113–189
Fish (fresh, all types) 380–689 120–290 28–144
Legumes Chick-pea 406–463 34–106 50–94
Cowpea 394–479 50–119 48–106
Soya bean 313–477 53–114 51–114
Cereals & grain products Barley 159–250 63–250 81–194
Maize 100–214 53–175 38–200
Millet 100–244 84–246 69–169
Rice (brown or husked) 198–263 117–194 30–79
Rye (whole meal) 151–281 59–181 85–156
Wheat (whole grain) 131–249 63–156 111–212
Roots and tubers Potato 163–488 54–125 7–81

The protein and indispensable amino acid profile of lean beef is reported in table 3. This is compared to the recommended protein requirement of 0.66 g/kg body weight/ day and the amino acid scoring pattern for children older than 3 years, adolescents and adults. According to the South African Food Based Dietary Guideline a serving of red meat can be eaten daily, but should not be more than 90g/day.

Table 3: Dietary protein and indispensable amino acid profile of cooked beef, cow’s milk, cooked soya beans compared to the recommended amino acid scoring pattern for children (3-10years), adolescents and adults

Cooked lean beef Full cream cow’s milk Cooked soya beans Recommended protein and amino acid scoring pattern for older children, adolescents and adults
“Crude” protein (g/100g) 31.8 3.25 18.21 0.66 g/kg/day50kg person = 33g

70 kg person = 46g

Amino acid
(mg/g total protein)
Histidine (His) 28 28 25 16
Isoleucine (Ile) 44 54 44 30
Leucine (Leu) 74 94 74 61
Lysine (Lys) 97 79 61 48
Sulphur amino acids (SAA) Methionine (Met) + Cysteine (Cys) 63 39 27 23
Aromatic amino acids (AAA) Phenylalanine (Phe) + Tyrosine (Tyr) 73 97 83 41
Threonine (Thr) 44 48 40 25
Tryptophan (Thp) 16 12 13 6.6
Valine (Val) 46 59 46 40

The study found that South African beef from all age groups adheres to the requirements as set out by the Department of Health to be labelled and proclaimed as a complete, quality protein.

It is of interest to note that the true protein was consistently lower in the cooked meat compared to the raw meat and that the different cuts varied in the respective amino acid profiles. While the measurement of crude protein (total nitrogen multiplied by a factor) is adequate for many purposes, amino acid data would provide a better assessment of the nutritional value of a food. Through this study the amino acid profile of South African lean beef was determined and is available for future studies.

Acknowledgement: This study was funded by Red Meat Research and Development of South Africa (RMRD SA) and the National Research Foundation Technology and Human Resources for Industry Programme (NRF-THRIP) (Project id: Tp1208076284).

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Prof H.C. Schonfeldt on

Blackfly outbreak predictive model

Development of a predictive management model for Orange River blackfly outbreaks

Industry Sector: Cattle And Small Stock

Research Focus Area: Animal Products, Quality and Value-adding

Research Institute: University of KwaZulu-Natal

Researcher: Dr Nicholas Rivers-Moore PhD

Research Team:

Title Initials Surname Highest Qualification
Dr Helen Dallas PhD
Dr Robert Palmer PhD
Mr Shahin Naidoo BSc (Hons)
Ms Esther Ndou BSc (Hons)

Year of completion : 2017

Aims Of The Project

  • To determine the amino acid profile of South African beef
  • To determine the validity of using nitrogen and a specific Jones factor to define protein quantity
  • To determine the protein quality of South African beef in the context of human nutrition

Executive Summary

Blackfly outbreaks on the Orange River impact on the agricultural sector through loss in conception, stock mortalities and loss in body weight gain, with losses of over R333 million pa. The Blackfly Control Programme has been in place for some twenty years, using a combination of bacterial and organophosphate applications at river breeding sites. This should have resulted in as many years worth of monitoring data, which, in analysis with flow data, would have provided a useful long-term dataset. Given acknowledged challenges, this has not been the case to the degree hoped for, with periodic outbreaks of blackfly continuing to occur, and the monitoring dataset being patchy and seldom evaluated. New thinking is needed that builds on existing research to reduce the chances of repeated outbreaks.

The aims of this study were threefold: to test and refine an existing Bayesian network predictive model of blackfly outbreaks; to undertake climate change scenario analyses to assist with future planning; and to provide an evaluation framework for blackfly monitoring data.

Fourteen sites between Douglas and Blouputs were monitored over four surveys: November 2015; March 2016; July 2016 and December 2016.

Data collected were blackfly samples (by species, density and relative abundances), hydraulic data (current velocities associated with multiple sample points per site), and water quality data (spot measurements of pH, conductivity, turbidity). Hourly air temperature data has been collected for 13 sites using Hobo TidBit data loggers, for 4 November 2015-5 December 2016. Water quality was fairly consistent between sites, but showed seasonal variation. Conductivity and pH had little impact on blackfly species patterns, with the exception of very high (> 1000μ conductivities in the irrigation return flow channels. Diatom data do, however, suggest that conductivities in the main Orange River have been increasing. Turbidity was a key driver in triggering ecosystem switching between dominance of pest blackfly species, and other blackfly species co-occurring with benthic algae.

Data confirm that the Orange River system switches between two states, viz. a high turbidity state favouring pest blackfly, and a clearer state favouring algal growth and where blackfly numbers are lower. Flow volumes and water temperatures affect turbidity levels, efficacy of larvicides, and availability of habitat for various ecosystem components (benthic algae, blackfly species). Thresholds were successfully identified from the abiotic-biotic relationships, which were incorporated into a Bayesian network model to predict the probability of blackfly outbreaks.

A predictive management framework was successfully constructed. An evaluation framework where ongoing monitoring by the Department of Agriculture, Forestry and Fisheries, and stakeholder involvement has been integrated through the development of a mobile phone App with an associated website. These are available through the Google Play App store (search for “Muggies”) and at respectively. These also include links to two YouTube videos explaining how to download the App and to upload data, with explanations of the scoring systems. All data uploaded makes use of Google Pins, so that the data are geo-referenced. Model predictions are available to users.

Additional comments

A follow up article in Landbouweekblad has been confirmed with Landbouweekblad staff. Both MSc studies are due to be submitted in the next 1-3 months respectively. Two scientific papers from this research are currently being prepared for submission and review.


  • To test and refine the recently developed pilot probabilistic blackfly outbreak model by inclusion of temperature and turbidity data, and using previous flows and monitoring data
  • To undertake climate change scenario analyses to assist future management planning
  • To provide an evaluation framework for monitoring data of blackfly larval densities, based on the outbreak model


Boere wen oorlog teen muggies

Dr. Nick Rivers-Moore.

Boere in die omgewing van die Middelen Benede-Oranjerivier kan nou danksy tegnologie en ’n nuwe model help om muggie-uitbrekings beter te bestuur.

Met die selfoontoepassing Muggies kan enigiemand inligting deurgee wanneer groot getalle muggies in die 1 200 km van die Oranjerivier tussen Hopetown en Sendelingsdrif voorkom.

Die inligting sal saam met ander gereelde waarnemings deur die staat in ’n nuwe voorspellende bestuursmodel gebruik word om groot uitbrekings van muggies beter te kan bekamp. Die model, die toepassing en die webwerf is in ’n navorsingsprojek ontwikkel wat in Julie vanjaar voltooi is. Die navorsing, onder leiding van dr. Nick Rivers-Moore, is deur die Waternavorsingskommissie (WNK) en die nasionale organisasie vir rooivleisnavorsing en -ontwikkeling (RMRDSA) gefinansier.


Die skade wat veeboere, spesifiek skaapboere, in dié gebiede aan die Oranjerivier ly, is sowat tien jaar gelede op minstens R300 miljoen per jaar geraam. Mnr. Hoffie Joubert, lid van Agri SA se nasionale waterkomitee belas met die uggieprobleem, sê dit is nou waarskynlik baie meer.

Luidens die jongste navorsingsverslag, Development of a Predictive Management Tool for Orange River Blackfly Outbreaks, kom verskeie muggiespesies in die gebied voor, maar dit is veral Simulium chutteri wat boere laat skade ly. Die ander spesies wat probleme veroorsaak, is S.damnosum, S. nigritarse en S. adersi. Volwasse wyfies van S. chutteri en S. damnosum voed op soogdiere se bloed, en laasgenoemde twee s’n op voëls.

Nick sê mannetjies vreet nek- tar en stuifmeel. Wyfies vreet ook hoofsaaklik nektar, maar het soos muskiete proteïen uit bloed nodig vir hul eiers om te ontwikkel. Dit is egter nie net skape en dus boere wat geraak word nie. Uitbrekings van muggies raak ook die toerismebedryf en inwoners van die omgewing. Die ergernisvlakke raak in ’n uitbreking van muggies so hoog dat werkers nie kan werk nie en toeriste sulke gebiede vermy. Luidens die verslag word die bestuur van die probleem bemoeilik omdat daar verskeie groepe met verskillende belange is, wat teen mekaar opgeweeg moet word. Ideale omstandighede vir groot uitbrekings hou onder meer verband met die volume water wat in die rivier vloei. Muggies hou van troebel water wat vinnig vloei. “Wanneer water stadiger vloei, is dit helderder. Water wat vinniger vloei, is troebeler. S. chutteri voed op sy doeltreffendste met watervloei van meer as 100 m per sekonde of ’n spoed van meer as 1 m/sekonde,” sê Nick.

Die vloei van die Oranjerivier het deur die jare aansienlik verander vanweë verskillende waterskemas, soos die Vanderkloofdam sedert 1977, die Gifkloofdam sedert 1971 en dan ook meer onlangs die Lesotho-Hooglandwaterprojek.
Veeboere verkies dalk ’n laer watervloei om uitbrekings van muggies te voorkom, maar besproeiingsboere met wingerd het meer water nodig, en Eskom het ’n bepaalde watervloei nodig om hidro-elektrisiteit op te wek.

Luidens die verslag moet ’n mens onthou dat hoewel muggies as ’n plaag beskou kan word, is dit ook ’n belangrike bron van voedsel vir baie roofdiere in die water is. “Die bestuursdoelwit behoort eerder die beheer as die uitwissing van muggies te wees.”


Die uitbrekings van muggies kom van tyd tot tyd voor. Die jongste een was in 2011 en voor dit in 2000-’01. Die staat het in die vroeë 1990’s met bestrydingsprogramme begin. Dit behels die toediening van ’n larwedoder vanuit ’n helikopter. Dit word gewoonlik drie keer in die herfs en ses keer in die lente toegedien. Twee middels is in Suid-Afrika vir die bestryding van muggies geregistreer: Vectobac® ( L7224, Wet 36/1947) en Abate® ( L2413). Opvolgnavorsing is onder meer tien jaar later gedoen om te kyk na alternatiewe larwedoders weens weerstandigheid by larwes teen temefos, ’n bestanddeel van Abate®.

Ondanks die bestrydingsprogram het uitbrekings steeds voorgekom, wat mense skepties laat raak het. Luidens die verslag hang die sukses van die program baie af van die korrekte tydsberekening van die toediening. Die redes vir die herhaalde en voortdurende uitbrekings is ingewikkeld. Dit sluit in hoër as normale watervloei in die winter, veranderinge in troebelheid, afwisseling van die oorheersende muggiespesie, larwedoderweerstandigheid en bestuurskwessies.


Verskeie pogings is al aangewend om die voorkoms van uitbrekings te verminder, waaronder ’n geïntegreerde bestrydingsprogram en voortgesette monitering, ’n waarskynliksheidsmodel om te kan voorspel wanneer volwasse wyfies ’n groot ergernis kan wees, optimalisering van larwedodertoedienings en die skep van ’n advieskomitee. Nie een het die gewenste gevolge gehad nie. As deel van navorsing in 2014 is onder meer vasgestel dat die mees onlangse uitbrekings waarskynlik eerder aan bestuurskwessies as biologiese kwessies toegeskryf kan word. Verder taan belanghebbendes se belangstelling gewoonlik wanneer die probleem nie groot is nie, en verhoog eers weer wanneer daar ’n uitbreking is.
“Die probleem is tipies van die meeste plaagbestrydingsprogramme, en wys op die behoefte aan langtermyntoesig,” lui die verslag.

Die doelwitte van die jongste navorsing het ingesluit om ’n voorspellende model te ontwikkel, vir die eerste keer data oor troebelheid en watertemperatuur in te sluit, en ook te kyk na die moontlike invloed van klimaatsverandering. Alle vorige navorsingsinligting is wéér ontleed, maar dié keer saam met nuwe inligting wat in 2015 en 2016 ingesamel is. Dit het onder meer weeklikse troebelheidsen uurlikse watertemperatuurinligting ingesluit. Seisoenale insamelings van larwes en papies is ook in verskillende hidrolitiese biotope en habitatte gedoen om seisoenale veranderinge in die betreklik hoë voorkoms van verskillende muggiespesies te kan verstaan. Om die moontlike invloed van klimaatsverandering te kan bepaal, is inligting van die Universiteit van KwaZulu-Natal se departement hidrologie gebruik, wat aandui watervloei kan in die nabye toekoms 60% hoër wees.


Die belangrikste bevindings van die jongste navorsing is: Die gehalte van water by die verskillende terreine was redelik dieselfde, maar het volgens seisoene gewissel. Die geleidingsvermoë van water en die pH-vlakke het ’n klein invloed op die patrone van muggiespesies gehad. Troebelheid was ’n sleutelrede vir ’n ander muggiespesie om die oorheersende een te word. Die water se vloeivolume en temperatuur het ’n invloed op troebelheidsvlakke, die doeltreffendheid van larwedoders en die beskikbaarheid van habitat vir verskeie ekostelsel-onderdele. Drempels is in die muggies se abiotiese-biotiese-verhoudings geïdentifiseer en in die model ingesluit waarmee die waarskynlikheid van uitbrekings van muggies voorspel kan word.


Vir die voorspellende bestuursraamwerk om suksesvol te wees, moet die insameling van inligting oor konsentrasies van muggies voortgaan. Inligting moet ook ingesamel word oor troebelheid en die voorkoms of afwesigheid van bentiese alge, wat verband hou met troebelheid. Al hierdie inligting moet, tesame met die lastigheidsindeks, op die webwerf gelaai word.
Die voorspellingsmodel moet dan met die inligting bygewerk en die verskillende data-onderdele moet van tyd tot tyd geoudit word. Wat egter ook baie belangrik is, is dat ’n “kampvegter” na vore moet tree, wat die raamwerk sal administreer en die maandelikse tariewe sal betaal vir die webwerf en die selfoontoepassing.

Die navorsers stel ook voor dat die ekonomiese invloed van muggies in die streek hersien word. Hoffie is opgewonde oor die bevindinge in die jongste navorsing en verwelkom die voorstel dat weer na die ekonomiese invloed gekyk word. “Inligting oor die omvang van die ekonomiese skade is belangrik vir die regverdiging van die toediening van larwedoder.” Hy sê die invloed van die gehalte van water op die toediening van middels moet ook nagevors word. Tans steun die plaagbestrydingsprogram net op die gebruik van Vectobac®, ’n organiese middel, weens die weerstand wat teen Abate®
ontwikkel het. Abate® het egter ’n baie groter reikafstand.

Hoffie sê die voorgeskrewe tydperk wat Abate® nie gebruik kon word nie, is nou verstreke en dit is belangrik dat dit weer getoets word. Agri Noord-Kaap gaan boere aan die rivier uitwys om die toepassing te gebruik om inligting oor muggies deur te gee en die organisasie sal dit monitor.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project –
Nicholas Rivers-Moore on blackfly1@vodamailcom

Characterization of breed additive and heterosis effects

Characterization of breed additive and heterosis effects in beef cattle using experimental results

Industry Sector: Cattle and Small Stock

Research focus area: Livestock production with global competitiveness

Research Institute: ARC-Animal Production Institute, Northern Cape Department of Agriculture, Land Reform and Rural Development

Researcher: Prof Michiel M Scholtz D.Sc. Agric

Research Team:

Title Initials Surname Highest Qualification
Ms A Theunissen
Dr MD MacNeil PhD
Prof FWC Neser PhD
Mr M Mpayiphheli
Mr P Coetzee
Ms L Botha

Final report approved: 2017

Aims of the project

  • To characterize and quantify crossbreeding heterosis in South African beef cattle using experimental results.
  • To estimate input values based on South African information to simulate breeding objectives in crossbreeding systems for South African conditions.
  • To calculate heterosis values based on South African information that can be used in the estimation of multibreed EBV’s.

Executive Summary

The aim of this study was to characterize the breed additive and heterosis effects in beef cattle using experimental results of 34 genotypes born from Afrikaner and Bonsmara as dam lines, using the experimental results of Els (1988) and De Bruyn (1991). During the study it became clear that the Afrikaner and Bonsmara cannot be analyzed in the same analyses due to difference in the mating plan and number of records between the two breeds. The results are therefore reported separately.
The aim of the study was to estimate direct and maternal additive and heterosis effects with the Afrikaner as dam line for (1) growth traits (birth weight, weaning weight, 19-month weight of heifers and cow weight) (2) fertility traits and feedlot and carcass traits from five purebred and 24 crossbred breed types. Afrikaner (A), Brahman (B), Charolais (C), Hereford (H) and Simmentaler (S) were evaluated as purebreds and as sire breeds on A and F1 BA, CA, HA and SA females. Breed additive effects were expressed as deviations from A. Effects of intra-breed genetic trend were assumed to be zero throughout. Solutions for the breed additive and heterosis effects were used to predict performance of the crossbred breed types to verify the adequacy of the genetic model.

Growth traits

Breed direct effects were consistently greatest for C and least for A across all traits, and maternal effects were greatest for S (except for 19-month weight) and least for C. Direct and maternal heterosis, on average, were positive for all weights. The indicus x sanga and indicus x taurus direct heterosis effects on all weight traits were greater than either the taurus x sanga or taurus x taurus effects, whereas the indicus x sanga maternal heterosis effect was consistently less than the estimated taurus x sanga maternal heterosis effect.

Fertility Traits

The average direct heterosis contributions, which were expressed as deviations from A, were +14.9, +109.1, -162.7, +21.0 and 15.4% respectively for conception rate (CR), calving difficulty (MB), pre-weaning mortality (MW), weaning percentage (WP) and weaning rate (WR) for ten two-breed genotypes. Similarly, the average maternal heterosis effects in four A crossbred dam genotypes were 0.0, -87.5, +97.7, -1.9 and -7.4% for the fitness traits respectively. The HA genotype had the highest expected WR of 83.1% in two-breed genotypes. The ACA, AHA and BHA genotypes had the highest expected WR of 86.9, 86.8 and 83.0% respectively.

Feedlot and carcass traits

Average direct heterosis was 17.9% for average post-weaning daily gain, being the largest in the B genotypes. The average maternal heterosis effects were less. Both average direct and maternal heterosis effects were essentially nil for daily feed intake, dressing percentage and percentage meat yield.
The aim of this study was to estimate the additive and non-additive effects for weight traits in two-breed crosses with the Bonsmara (Bo) as dam line and the Simmentaler (S), Brahman (B), Charolais (C) and Herefords (H) as sire lines. The average direct heterosis contributions, which were expressed as deviations from Bo were 1.41 kg, and 13.64 kg for birth weight (BW) and weaning weight (WW) respectively in the four crossbred genotypes.  The largest additive effect for BW was found in C x Bo while WW largest in S x Bo. The results indicate that C and S bulls could increase WW in the progeny of Bonsmara cows. C bulls should be used with caution due the additive effect on BW. The use of B and H sires on Bonsmara cows is not recommended due to the negative additive effect on WW. It needs to be mentioned that Els (1988) reported weaning rates (number of calves weaned as percentage of number of cows exposed to mating) 100.0, 96.6, 91.8, and 97.6 % for the B x Bo, C x Bo, H x Bo and S x Bo dam groups respectively. This may indicate an extremely high fertility in Bonsmara crossbred cows.


  • M.Sc thesis by Anette Theunissen – UFS. “Characterization of breed additive and heterosis effects in beef cattle using experimental results.”

 Conferences and Symposia 

  • THEUNISSEN, A, SCHOLTZ, M M & NESER, F W C, 2011. Crossbreeding heterosis in beef cattle in arid areas. 44th Congress of the South African Society for Animal Science, 11 – 14 July 2011, Stellenbosch, South Africa
  • THEUNISSEN, A, SCHOLTZ, M M & NESER, F W C, 2012. Crossbreeding in beef cattle with reference to the South African situation – a review. 45th SASAS Congress, 9 – 12 July 2012, East London, South Africa
  • THEUNISSEN, A, SCHOLTZ, M M & NESER, F W C, 2012. Crossbreeding to increase beef production: Additive and non-additive effects on weight traits. 45th SASAS Congress, 9 – 12 July 2012, East London, South Africa
  • THEUNISSEN, A, MACNEIL, M D, SCHOLTZ, M M & NESER, F W C, 2013. Breed additive and heterosis effects in crossing the indigenous Afrikaner breed with exotic beef breeds in South Africa. 11th World Conference on Animal Production. 15 – 20 October 2013, Beijing, China, 171.
  • MOKOLOBATE, M C, SCHOLTZ, M M, NESER, F W C & MULGETA, S D, 2013. Sustainable beef cattle crossbreeding systems in the era of climate change. Proc. 46th Congress of the South African Society for Animal Science, 23 – 26 June 2013, Bloemfontein, South Africa.
  • THEUNISSEN, A, SCHOLTZ, M M, NESER, F W C and MACNEIL, M D, 2013. Crossbreeding to increase beef production: Additive and non-additive effects on fitness traits. Proc. 46th Congress of the South African Society for Animal Science, 23 – 26 June 2013, Bloemfontein, South Africa.
  • THEUNISSEN, A, SCHOLTZ, M M, NESER, F W C and MACNEIL, M D, 2013. Additive and non-additive effects on feedlot and carcass traits. Proc. 46th Congress of the South African Society for Animal Science, 23 – 26 June 2013, Bloemfontein, South Africa.
  • THEUNISSEN, A, MACNEIL, M D, SCHOLTZ, M M & NESER, F W C, 2013. Breed additive and heterosis effect in crossing the indigenous Afrikaner breed with exotic beef breeds in South Africa. 3rd Global Conference on Agriculture, Food Security and Climate Change, 3 – 5 December 2013, Johannesburg, South Africa.

Scientific articles

  • SCHOLTZ, M M, McMANUS C, OKEYO, A M & THEUNISSEN A, 2011. Opportunities for beef production in developing countries of the southern hemisphere. Livestock Science, 142: 195 – 202
  • THEUNISSEN, A, SCHOLTZ, M M & NESER, F W C, 2013. An overview of crossbreeding in beef cattle with reference to the Southern African situation. Applied Animal Husbandry & Rural Development, 6, 18 – 21.
  • THEUNISSEN, A, SCHOLTZ, M M, NESER, F W C & MACNEIL, M D, 2013. Crossbreeding to increase beef production: additive and non-additive effects on weight traits. South African Journal of Animal Science, 43 (2): 143 – 152
  • THEUNISSEN, A, SCHOLTZ, M M, MACNEIL, M D & NESER, F W C. Breed Additive and Heterosis Effects on Feedlot and Carcass Traits in  Beef Cattle. Journal of Animal Science (submitted)
  • THEUNISSEN, A, SCHOLTZ, M M, MACNEIL, M D & NESER, F W C. Crossbreeding to increase beef production in South Africa: additive and non-additive effects on fitness traits. South Africa Journal of Animal Science (submitted).

Popular articles and media

  • THEUNISSEN, A & SCHOLTZ, M M, 2012. Kruisteelt vir die toekoms. Red Meat / Rooivleis, 3 (4), 64 – 67
  • THEUNISSEN, A & SCHOLTZ, M M, 2013. Kruisgeteelde en komposietbulle: Waar lê hul waarde? Veeplaas, September 2013, 81-83
  • THEUNISSEN, A & NESER, F W C, 2013. Different cross breeding systems for increased profit. Aldam Stockman’s School. 16 – 18 October, 3013.

Literature Review

  • Crossbreeding in beef cattle with reference to the South African situation – Phillip Coetzee. Honours seminar at University of the Free State.
Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Michiel Scholtz on

The food composition of raw and cooked beef offal

The food composition of raw and cooked beef offal (A Pilot study, as a pro-active activity)

Industry Sector: Cattle and Small Stock

Research focus area: Red Meat Safety, Nutritional Quality and Value

Research Institute: ARC-Animal Production Institute

Researcher: Dr SM van Heerden

Research Team:

Title Initials Surname Highest Qualification
Dr LE Smit
Mrs MM Magoro
Dr IB Zondagh PhD
Mrs JM Van Niekerk
Mrs JM Masilela
Mrs C Rapelego

Final report approved: 2017

Aims of the project

  • To determine selected nutrients in a pilot study of raw and cooked, red and white South African beef offal
  • To determine the total profile of nutrients should the results from the pilot study indicate the need for this?
  • To make the data on the nutrient composition of South African beef offal available to the MRC to be included
  • Into the South African Food Composition Tables of the Medical Research Council (MRC)
  • To compile and publish a comprehensive booklet on the nutrient content of South African beef offal

Executive Summary

Scientific literature on the nutrient content and food composition tables of offal is relatively scarce. However the nutritive value of all food products including meat and meat products is important, in view of the consumer interest and demand for a healthier lifestyle (Pearson & Tauber, 1984). Therefore, there is a great need for more detailed information on food with adequate nutritive value, especially protein, for the informal and poorer sections of the population in South Africa.

With the WHO’s estimation that 5 million people are dying every year from starvation, more attention should be given to the possibility of using proteins such as offal (beef, sheep), as protein sources in the diet (Poonam & Lawrie, 1986:144).

Offal, or organ meats, refers to the internal organs and entrails of a butchered animal, makes up a substantial portion of an animal’s meat weight. The word does not refer to a particular list of edible organs, but includes most internal organs other than muscle and bone. It is also described as those parts of a meat from a carcass which are used as food but which are not skeletal muscle. It covers insides including the heart, liver, and lungs (collectively known as the pluck), all abdominal organs and extremities: tails, feet, and head including brains and tongue. In the USA the expressions “organ meats” or “variety meats” are used instead (

In South Africa offal is mostly enjoyed by South Africans of diverse backgrounds. Due to the popularity of this dish, it is one of the few customs that white (especially Afrikaners) and black South Africans share. Offal dishes in South Africa include stomach, hooves, shin, intestines, liver, head, tongue and very rarely in certain communities, testicles, and are consumed ‘fresh’ (i.e. not frozen).

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Ina van Heerden on

Brine injection of beef

The effect of moisture enhancement by brine injection on the chemical, microbial and sensory quality of beef

Industry Sector: Cattle and Small Stock

Research Focus Area: Animal Products, Quality and Value-adding

Research Institute: Agriculture Research Institute – Animal Production Institute

Researcher: Dr Phillip Strydom PhD Animal Science

Title Name Surname Highest Qualification
Prof CJ Hugo PhD
Dr C Bothma PhD
Dr C Charimba PhD
Mr M Cluff M.Sc Agric
Ms E Roodt M.Sc Agric
Mr Z Kuhn B.Sc Agric Hons
Mr H Steyn B.Sc Agric Hons
Ms E Moholisa M.Sc Agric
Dr M Hope-Jones PhD
Ms JM Boikhutso MInst. Agrar: Food Production and processing
Ms MM Magoro M.Tech.Food Technology
Mr CA Seomane Grade 8, Meat Technology Research Assistant, 27 years’ experience
Mr WK Seanego Grade 7,Meat Technology Research Assistant 11 years’ experience
Dr SM Van Heerden PhD
Ms OC Sehoole BSc Food management (4 years)
Ms TM Mokhele BInstAgrar Food Processing (4 years)
Ms JH Masilela Grade 9, sensory research assistant 26 years experience

Aims Of The Project

  • To determine the effect of injection of non-nitrite moisture enhancing injection brines on the nutritional value of beef.
  • To determine the effect of injection of non-nitrite moisture enhancing injection brines on the chemical and microbial stability of beef under refrigerated and frozen storage.
  • To determine the effect of injection of non-nitrite moisture enhancing injection brines on the textural and sensory properties of beef.

Year of completion : 2017

Executive Summary

The effect of different injection levels of non-nitrite brines on meat quality characteristics of unaged and aged beef loins was investigated. Beef loin cuts aged for 3 or 10 days were injected with 5, 10, 15 or 20 % brine (weight basis) and compared with non-injected loins with regards to nutritional value, sensory and textural quality, water holding properties, and colour, chemical and microbial stability.

The results illustrated that brine injected in beef loin are retained between 50 to 70 % of injection levels. This resulted in a clear nutrient dilution, best illustrated by the decrease in protein content from 21.1 % in the Control loins to 18.5 % in the loins injected to a target yield of 20 %. The dilution of protein became evident only at an injection level of 10 % and higher but did not increase further with higher levels of injection. Brine injection also increased the levels of phosphate (35 %) and salt (50 %) and the effect was consistent across all injection levels. This is very important since salt and sodium content of especially meat products are currently under the spotlight with new legislation on sodium levels of meat products being implemented on 30 June 2016.

The chemical stability of beef loin as measured by TBARS (measurement of rancidity) was not affected by brine injection. Neither fresh samples, displayed for 6 days, or frozen samples, stored for 180 days, were affected, despite the fact that salt is a pro-oxidant and chemical deterioration was expected with brine injection.

Colour and colour stability were affected by brine injection. Initial colour (just after treatment) measured as chroma (typical colour of fresh meat) was negatively affected only at injection levels above 10%. However, as days on display continued (up to 6 days), all injected samples showed poorer colour stability (lower chroma values) than Control samples. Likewise, injected samples were duller (lower values for lightness, L*).

Brine injected samples tended to show higher initial (day of injection) total aerobic micro-organism counts (0.5 – 0.7 of a log) likely due to the recirculation of the brine during application. However, microbial growth was later (day 6 on the shelf) inhibited, probably by the potassium lactate in the brine mix, eventually leading to the brine injected samples having lower total aerobic bacteria loads (between 0.5 and 0.8 of a log) than Control samples. Also because of recirculation of brine, yeasts and molds were higher in injected samples (0.8 to 1.0 log) after injection, but differences between Controls and injected samples became insignificant after 6 days on the shelf.

Both Warner Bratzler shear force and sensory tenderness showed beneficial effects due to brine injection even at levels as low as 5 %. A slight linear increase (lower shear force and higher tenderness score) was observed with increasing level of injection although the effect was not statistically significant above 10 % injection level. The taste panel also scored injected samples higher for juiciness and although these scores increased slightly with level of injection, no significant effect was observed above 10% levels. As expected, the taste panel also scored injected samples higher for saltiness, but no off-flavours were identified.

Another advantage of brine injection was a reduction in thawing and total cooking losses. The maximum effect was observed at 5 % injection level and cooking loss slightly increased as injection level increased.

In conclusion, it seems that the advantages and disadvantages of brine injection is correctly balanced by the 10% brine injection limit enforced by the Agricultural Product Standards Act, 1990 (ACT No. 119 of 1990; 30 January 2015) for beef. Brine injection levels above 10% showed no additional effect on eating quality. Likewise, the negative effect on colour of freshly displayed meat deteriorated at levels above 10%, while the protein dilution effect also became evident at 10% level. Higher salt irrespective of injection level may be a health concern.

Popular Article

Phillip E. Strydom1,2*, Zarlus Kuhn3, Celia J. Hugo3 and Arno Hugo3

  1. Animal Production Institute, Agricultural Research Council of South Africa, Irene, 0062, South Africa
  2. Department of Animal Sciences, Stellenbosch University, Stellenbosch, 7602, South Africa.
  3. Department of Microbial, Biochemical and Food Biotechnology, University of Free-State, Bloemfontein, South Africa.
    *Corresponding author email:

Abstract – The enhancement of beef, pork and chicken with brine solutions has become common practice in many countries.
The combined effects of aging and brine injection level on beef quality is unknown. Our study investigated the effects of five
brine injection level (0, 5, 10, 15 20%) combined with post mortem aging period (3 and 10 days) on sensory characteristics of broiled beef loin. Injected samples were scored higher for saltiness but aging reduced the effect. Brine injection had no effect on flavour but tenderness was improved up to 15% injection level. Apart from 0 and 5 % injection levels, aging had no effect on tenderness score. Juiciness was improved up to 10% injection level after 10 days aging and up to 5 % injection level for 3-day aged cuts. The results suggest that a maximum of 15% brine injection will give the best sensory results and save on post mortem aging time.

Key Words – tenderness, juiciness, saltiness.

Brine injections have been used in the poultry industry since the 1950’s [1]. Red meat processors saw this technology
as an opportunity to improve beef and pork palatability that deteriorated as a result of the production of increasingly
leaner animals that contain less fat [2,3,4], although atypical flavours may also develop [2, 3]. Hamling et al. [5] found
that post mortem aging could be substituted by brine injection. High levels of injection may not necessarily improve
eating quality while other negative effects such as purge may also occur [6]. The abuse of brine injection of poultry meat
in the South Africa resulted in legislation stipulating a maximum of 10% to 15% brine for whole carcasses and portions,
respectively after extensive research. However, brine injection of beef in South Africa was limited to 10% without any
scientific verification [7]. Our study investigated the effects of post mortem aging and brine injection levels on sensory
quality of loin cuts of young grain-fed beef.

Sixty beef loin primal cuts were subjected to five brine treatments: a non-injected control and four groups respectively injected to 5, 10, 15, and 20% level with a salt, sodium tripolyphosphate (STPP), potassium lactate containing brine; and two aging periods: 3 and 10 days post mortem. Loin steaks were oven-broiled and evaluated by a ten-member trained sensory panel on an 8-point hedonic scale for aroma, juiciness, tenderness/texture, beef flavour intensity,
metallic/tin-like/bloody, chemical (salty), and sour off-flavours. Data were subjected to analysis of variance for a splitplot
design with injection level as whole plots and days post mortem as sub-plots.

Despite adding salt to the control samples, injected steaks scored higher values for saltiness, although level of injection
did not have an effect (Table 1). The effect of injection was less for cuts aged 10 days than for those aged 3 days. Knock
et al. [4] reported higher scores for typical beef flavours, when beef loins were enhanced with KCl brine to 8.5% level,
especially after 9 days aging. Although the different brine levels in our study had similar levels of salt, Knock et al. [4]
showed higher scores for saltiness and rancidity when salt levels were increased. In contrast to our study, Grobbel et al
[3] reported off-flavours, such as salty, metallic or chemical descriptors for brine injected beef loin. Injected steaks
scored higher for tenderness in our study irrespective of aging period. Higher injection levels generally gave better
results, although the effect plateaued at 15% injection level for 3 day aged steaks and at 10% injection level for steaks
aged for 10 days. Injected steaks also scored higher for juiciness. The effect of injection level on juiciness plateaued at
10% for steaks aged for 3 and at 5% for steaks aged for 10 days. Knock et al. [4] found no effect of brine injection will follow later (8.5%) on beef loin tenderness or juiciness, while Hoffman et al. [2] reported similar results as our study for four unaged muscle types injected to a 15% level. Hamling et al. [5] reported higher scores for tenderness, flavor and juiciness at 20% injection levels and this was unaffected by aging to 14 days. In our study, added effects of aging on tenderness and
flavour were found at 5 % injection level. Aging had no effect on juiciness perception, but 10 day aged samples injected
to 10 and 15% levels scored lower than 3 day aged samples. Likewise, all 10 day aged injected samples, except 20%,
scored lower for saltiness than 3 day aged samples.

Ten percent seems to be the optimum injection level for improved juiciness and tenderness of loin primals, while flavour
is not affected by brine injection. Perception of saltiness due to brine injection is reduced when samples are aged. In
general, brine injection can save on post mortem aging time with regards to improvement of tenderness.

PE Strydom thanks Dr Ina van Heerden and her sensory team for sample testing.

1. Buchanan, B. F. (1955). Process for Treating Poultry. United States Patent Office. Patent 2 709 658, application 17
April 1951. pdfs/US2709658.pdf.
2. Hoffman, L. C., Vermaak, A., & Muller, N. (2012). Physical and chemical properties of selected beef muscles
infused with a phosphate and lactate blend. South African Journal of Animal Science 42: 317–340.
3. Grobbel, J. P., Dikeman, M. E., Hunt, M. C., & Milliken, G. A. (2008). Effects of different packaging atmospheres
and injection-enhancement on beef tenderness, sensory attributes, desmin degradation, and display color. Journal of
Animal Science 86: 2697–2710.
4. Knock, R. C., Seyfert, M., Hunt, M. C., Dikeman, M. E., Mancini, R. A, Unruh, J. A., & Monderen, R. A. (2006).
Effects of potassium lactate, sodium chloride, and sodium acetate on surface shininess/gloss and sensory properties
of injection-enhanced beef strip-loin steaks. Meat Science 74: 319–326.
5. Hamling, A. E., Jenschke, B. E., & Calkins, C. R. (2008). Effects of aging on beef chuck and loin muscles enhanced
with ammonium hydroxide and salt. Journal of Animal Science 86: 1200–1204.
6. Miller, R. 1998. Functionality of non-meat ingredients used in enhanced pork. Pork Quality Facts. National Pork
Board, Des Moines, IA, pp. 1–12.
7. Government notice No. 55 of 30 January 2015. Regulations regarding the classification and marketing of meat.
Department of Agriculture, Forestry and Fisheries, Republic of South Africa. files/38431_reg10358_gon55.pdf.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project –  Dr Philip Strydom on

Heterosis effects on beef sensory and leather quality traits

Characterization of breed-specific additive and heterosis effects on beef sensory and leather quality traits

Industry Sector: Cattle and Small Stock

Research Focus Area: Research Animal Products, Quality and Value-adding

Research Institute: ARC-Animal Production Institute Northern Cape Department of Agriculture, Land Reform and Rural Development and University of the Free State

Researcher: Prof Michiel M Scholtz D.Sc. Agric

Title Initials Surname Qualification
Mrs A Theunissen MSc Agric
Dr M.D. MacNeil Ph.D
Dr P.J. De Bruyn Ph.D
Prof F.W.C. Neser Ph.D

Year of Completion : 2017

Aims Of The Project

  • To characterize the maternal and paternal heterosis effects on sensory beef traits
  • To characterize the maternal and paternal heterosis effect on leather traits

Executive Summary

The project had two objectives, namely to estimate direct and maternal breed effects and heterosis contributions for Afrikaner (A), Simmentaler (S), Brahman (B), Charolais (C) and Hereford (H) on sensory carcass traits and leather traits.

Sensory carcass traits

Five sensory traits (tenderness, juiciness, aroma and flavor and residual connective tissue) and two physical meat traits viz shear force (N/2.5cm2) and cooking loss (%) were investigated. Data (N=375) arising from 5 straightbred and 24 crossbred combinations were modeled by multiple regression of the phenotypes on expected breed roportions and heterozygosity.

Only direct effects seem important for shear force, tenderness, and residual connective tissue. However, for juiciness and cooking loss maternal effects also seem relevant. This may indicate that effects manifested during the pre-weaning period on components of meat quality were retained through the time of harvest or a predisposition for creating differences in the sensory properties of the meat were established. The indigenous Afrikaner had generally the most favourable sensory profile relative to the imported breeds. This was particularly true for shear force and tenderness.

Sanga cattle, like the Afrikaner, are early maturing breeds. There is clear evidence that the use of exotic germplasm on Sanga breeds can increase feedlot performance and meat yield of cattle reared under South African conditions. Different crossbred genotypes also provide opportunity for more rapid conformation to the changes in market requirements and may offer opportunity for more revenue. However, it appeared based on the sensory data summarized, that crossbreeding with exotic germplasm has little to offer in terms of consumer satisfaction relative to the use of Afrikaner.

Leather quality

It is important to note that hides are normally purchased by weight, but leather is sold by surface area. It is therefore common practice to mechanically stretch the hides during tanning and manufacture. The standard practice is to stretch leather to 20% extension. There is however concern that this stretching may affect important aspects of leather quality and strength.

Hide yield (%) and 8 leather characteristics (leather yield (dm2/kg), force 20% extension (Mpa), extension grain crack (%), extension break (%), force break (Mpa), slit tear force (N/mm), distension grain crack (%), and force grain crack (N/mm)) were evaluated. The results indicate breed direct effects and individual heterosis, but not maternal effects, may be important for most of these traits. For all of the exotic breeds, direct effects reduced hide yield and increased leather yield relative to the indigenous Afrikaner. For both of these traits, individual heterosis effects arose primarily from indicus x taurus crossing with the Hereford x Brahman effect being most pronounced. Leather from the exotic breeds appeared to be stronger, as evidenced by greater direct effects for force required to achieve 20% extension and break, than leather from the indigenous Afrikaner. Direct effects on the extension required to crack the grain attributable to Hereford and Simmentaler were less than for the indigenous Afrikaner, Brahman, and Charolais. These results indicate opportunities to improve leather yield and quality through crossbreeding relative to straight bred Afrikaner.

Popular Article

There are 2 scientific articles, please contact the researcher for more information on this.

Please contact the Primary Researcher if you need a copy of the comprehensive report of this project – Michiel Scholtz on