Thesis (Ph.D. ( Animal breeding)) --University of Limpopo, 2012 / Refer to document / the Agriculture Research Council

Thesis (M. Dev.) -- University of Limpopo, 2017 / There is a gap in the literature about the role and relevance of Indigenous Knowledge and beef cattle welfare in many parts of the Limpopo province. This gap is relevant because many marginalised cattle owners use indigenous knowledge in their day to day management of beef cattle. The aim of the study is to investigate the use of IK methods on beef cattle husbandry in Tshebela village in the Capricorn district of the Limpopo province as a contribution to filling the void identified above. The objectives of the study were as follows:  -To investigate the IK methods used in beef cattle husbandry in the area of the study;  -To assess if beef farmers use IK to identify medicinal plants to cure beef cattle;  -To investigate farmers‘ perceptions and attitudes on the use of IKS on beef cattle husbandry in the area of study. A qualitative methodology that was used was primarily phenomenological in design. A purposive sampling technique was used and twenty seven (27) traditional beef farmers, two (2) local herbalists were recruited as participants. Data was collected through focus group discussions, key informant interviews, and observations. An interpretative phenomenological-based analysis was used to surface the role and relevance of indigenous knowledge in beef cattle husbandry. The findings suggest that indigenous knowledge is used by cattle owners alongside modern knowledge and that communal farming posed some challenges to the farmers.

Thesis (M. Dev.) -- University of Limpopo, 2017 / There is a gap in the literature about the role and relevance of Indigenous Knowledge and beef cattle welfare in many parts of the Limpopo province. This gap is relevant because many marginalised cattle owners use indigenous knowledge in their day to day management of beef cattle. The aim of the study is to investigate the use of IK methods on beef cattle husbandry in Tshebela village in the Capricorn district of the Limpopo province as a contribution to filling the void identified above. The objectives of the study were as follows:  To investigate the IK methods used in beef cattle husbandry in the area of the study;  To assess if beef farmers use IK to identify medicinal plants to cure beef cattle;  To investigate farmers‘ perceptions and attitudes on the use of IKS on beef cattle husbandry in the area of study. A qualitative methodology that was used was primarily phenomenological in design. A purposive sampling technique was used and twenty seven (27) traditional beef farmers, two (2) local herbalists were recruited as participants. Data was collected through focus group discussions, key informant interviews, and observations. An interpretative phenomenological-based analysis was used to surface the role and relevance of indigenous knowledge in beef cattle husbandry. The findings suggest that indigenous knowledge is used by cattle owners alongside modern knowledge and that communal farming posed some challenges to the farmers

Thesis (MSc. (Pasture Science)) -- University of Limpopo, 2019 / An experiment was conducted at the University of Limpopo to determine the diet selection of cattle in the Petersburg Plateau Bushveld, the aim being to identify important and palatable grass species during four seasons of the year and to determine their above-ground biomass production. For diet selection data, five permanently marked transects were randomly laid out per camp, each 100 m long. On each transect, grass tufts were identified and permanently marked at 1 m intervals (100 tufts per transect). Turfs were surveyed on a weekly basis to determine frequency, intensity of utilization and tuft height. A palatability index was determined for each species. Diet selection data were analysed, using descriptive statistics. For biomass production, five permanent 20 m x 20 m plots were randomly laid out per camp, in which biomass of grass were measured. Within each plot, five 1 x 1 m quadrates were randomly harvested. The biomass data was analysed using the General Linear Mixed Model. Means were compared, using a Tukey test at the 5% significance level. Digitaria eriantha, Eragrostis rigidior and Heteropogon contortus were the dominant grass species. On average, Brachiaria nigropedata, Panicum maximum and Digitaria eriantha were utilized at higher frequencies and intensities. Brachiaria nigropedata, P. maximum, Urochloa mosambicensis, Themeda triandra, D. eriantha, Schmidtia pappophoroides and H. contortus were regarded as the most palatable species. The circumference of the tuft of S. pappophoroides, E. rigidior and D. eriantha decreased highly significantly (P<0.01). The height of utilizable leaves of B. nigropedata, D. eriantha, P. maximum and S. pappophoroides decreased highly significantly, while the height of highest leaves of B. nigropedata, D. eriantha, P. maximum, S. pappophoroides, H. contortus and T. triandra also decreased highly significantly. Total biomass production was significantly higher (P<0.05) during autumn, while total biomass production during winter was low, compared to other seasons. Total biomass production did not differ significantly between spring and summer. Panicum maximum, x B. nigropedata, D. eriantha, T. triandra, H. contortus, S. pappophoroides and U. mosambicensis were regarded as “key species” in the diet selected by cattle. Farmers in the Pietersburg Plateau Bushveld should graze their camps to assure the maintenance or improvement of perennial palatable grasses with high biomass production, which will result in overall improvement of veld condition.

Thesis (M.Sc.) (Agriculture) --University of Limpopo, 2007 / The objectives of this study were to evaluate the effect of pre-weaning selection on estimates of genetic parameters for post-weaning average daily gain in Phases C (ADG-C) and D (ADG-D) and to estimate genetic relationships between average daily gain in the two phases. Performance records of the South African Angus cattle breed was used in the analysis. (Co)variance components and genetic parameters for weaning (WWT), AGD-C and ADG-D were estimated by REML procedures fitting three different models (Models 1, 2 and 3) that differed in how they integrated sequential selection in the analysis of post-weaning traits. Model 1 was a univariate model of WWT, ADG-C and ADG-D. Model 2 was a two trait model of WWT and either ADG-C or ADG-D. Model 3 was a three trait model of WWT, ADG-C and ADG-D. Estimates of heritability for ADG-C were 0.39±0.08, 0.42±0.06 and 0.44±0.01 from Model 1, 2 and 3 respectively. Corresponding estimates of heritability for ADG-D were 0.18±0.021, 0.19±0.021 and 0.21±0.02 respectively. An estimate of genetic correlation between ADG-C and ADG-D was 0.58± and it suggested that the two traits may not necessarily be under the same genetic control. Rank correlations for all bulls based on ADG-C estimated breeding values (EBV’s) were 0.92, 0.83 and 0.94 for Model 1 vs. Model 2, Model 1 vs. Model 3 and Model 2 vs. Model 3 respectively. Corresponding ADG-D EBV’s rank correlations were 0.88, 0.84 and 0.93. Rank correlations for top and bottom 1%, 5% and 10% were lower than those for all bulls in both ADG-C and ADG-D. Low rank correlations showed that the difference in magnitude of genetic parameters from different models was enough to alter bull rankings based on EBV’s of ADG-C and ADG-D. Hence it was concluded that inclusion of pre-weaning information in genetic analysis for post-weaning average daily gain is necessary to account for selection at weaning. / the THRIP (Technology and Human Resource for Industry Project) and NRF (National Research Foundation).

Dairy farming is one of the most important agricultural industries in South Africa, and thus improving the performance of dairy cows, with respect to economically important dairy traits, would be beneficial. Selection of dairy cows has traditionally been phenotypic, but new molecular techniques have made it possible to evaluate phenotypic dairy traits at the DNA level, providing the possibility of more accurate selection. The economically important dairy traits, milk production and reproductive performance, are quantitative traits, and are therefore controlled by many genes and the environment. A number of genes have been identified that have been shown to influence economically important dairy traits, including the lep gene. This gene encodes the hormone leptin, which has been proven to regulate feed intake, energy balance, fertility and immune function. A polymorphism has been identified in the lep gene, which may be associated with economically important dairy traits. This study on a South African Jersey herd investigated the possible association of the polymorphism, RFLP-Kpn 21, with milk production and reproductive performance. The lactation records of fifty Jersey cows that completed their first lactation between 1997 and 2004 were collected, and these cows were genotyped for the RFLP-Kpn 21 polymorphism, located at exon 2 of the lep gene. This involved the extraction of DNA from venous blood, using a salting out technique. The extracted DNA was amplified using PCR primers; the reverse primer included a purposeful mismatch. The role of the purposeful mismatch was to create a recognition site for a restriction enzyme (Kpn 21), thus allowing the alleles of the polymorphism to be identified through a restriction digestion protocol. Two alleles were identified, the C- and the Tallele. The genotype of each cow was identified using PAGE. The significance of the genotype effects on the milk production traits and the reproductive performance traits were estimated using the F-statistic provided by a GLM Univariate analysis. In conclusion, no significant effect of the RFLP-Kpn 21 polymorphism was found for milk yield, butterfat and protein percentage, ICP and SPC (p > 0.05), but a possible association with lactose percentage was suggested by the statistical analysis (p < 0.05). Further investigation of South African Jersey cows will be necessary in order for conclusive results to be obtained. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Leptin, a 16 (kilo Dalton) kDa hormone secreted predominantly by white adipocytes, regulates reproduction, energy intake and expenditure, and is involved in immune system function. Previous studies have identified associations between polymorphism E2FB in the leptin gene (lep) of cattle and milk quality and quantity, feed intake, and fat deposition in dairy and beef cattle though further studies have shown inconclusive results. Furthermore, indigenous South African cattle have not been involved in lep investigations or the applicability of the marker in South African beef grading systems. An investigation was conducted into the association of an SNP of a cytosine (C) to thymine (T) SNP (single nucleotide polymorphism) mutation in exon 2 of the bovine lep (leptin) gene with weight gain, body condition, carcass fat content and quality in a population of indigenous Nguni cattle (n = 70) as well as a population of exotic British Hereford cattle (n = 54). The Hereford population had higher T-allele frequencies and a lower P-value (P = 0.172) for the E2FB genotypes than the Nguni population (P = 0.958). The resulting E2FB lep genotypes CC, CT and TT did not show an association with the pre- and post-slaughter traits initial live weight (ILW), body condition score (BCS), slaughter live weight (SLW), carcass fat content (FAT), carcass conformation (CFN) or warm carcass mass (WCM) for either population though t-tests revealed an association with the CT genotype with increased ILW than TT and a significantly higher WG in the TT genotypes than the CT (P<0.05). Subsequently, differences in pre- and post-slaughter traits in both populations were largely attributable to breed differences. The Hereford population exhibited significantly higher WG, CFN, SLW, WCM and CCM (P<0.05) than the Nguni population. The Nguni displayed significantly higher ILW and BCS values when graded in terms of the commercial South African AAA feedlot system. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Beef constitutes an important part of many consumers’ diets. Beef is the most consumed red meat in South Africa. Consumer perceptions can affect the whole supply or value chain of beef. Recently there has been increased interest in food safety; greater concern for environmental and animal welfare issues, increased importance of eating quality and healthy food as well as the greater role of food services. The demand for beef is no longer limited to economic factors alone but to non-economic factors as well. Consumers of beef in Alice have become more concerned about meat-borne risks and personal health. This research prioritized the exploration of the beef consumers’ (i) self-perception (ii) price perception (iii) benefit perception [in the form of – (a) value perception and (b) quality perception]. The study was conducted in the Eastern Cape Province specifically in Alice town and the surrounding rural areas (Ntselamanzi, Gaga, Hillcrest, Gqumashe, and Dyamala) of the Nkonkobe municipality. Anyone who admitted to eating beef and at the point of data collection bought beef for their own consumption or family consumption was deemed as a unit of analysis. Non – probabilistic sampling techniques which included accidental and random sampling were used to collect data from 100 interviewees. A semi structured questionnaire was used to analyse the perceptions and attitudes of beef consumers. The respondents were asked to indicate their agreement or disagreement with 47 statements or items presented on either five alternatives in a Likert scale scored from 1 (strongly disagree) to 5 (strongly agree) or a six Likert scale ranging from 1 (very low) through 5 (very high) to 6 (I do not know).The data was analysed using SPSS. It was discovered that beef consumers did not consider either intrinsic or extrinsic cues in isolation when purchasing beef but rather all characteristics contribute to the final perception. The Alice consumer market is heterogeneous and consists of different races with different cultures and market segments with varying needs and preferences. The results showed that five factors were extracted from forty seven items Factor 1: Information reliance and quality indication; Factor 2: convenience; Factor 3: Traceability and animal Welfare; Factor 4: Health and safety Conscious and Factor 5: Price and Branding. Furthermore, four main consumer segments emerged as - Segment 1: Informed buyers; Segment 2: Elite buyers; Segment 3: Health & safety conscious buyers and Segment 4: Apathetic buyers. The cluster analysis shows that quality is a subjective concept that is informed by a consumer’s personal taste and preferences. Taste and preferences inform the consumer’s effective demand which in retrospect is informed by the consumer’s socioeconomic status.

The objective of this study was to determine time budgets, blood urea content, total protein and body condition score as adaptive responses to seasonal dynamics by breeding Nguni cows and heifers reared on a sweetveld. Twenty four clinically healthy Nguni cows and heifers were selected for the study. The animals were grouped according to their parities namely: Parity 1 (n=5), Parity 2 (n=5), Parity 3-6 (old cows) (n=9) and in-calf heifers (n=5). Two separate experiments were conducted and running concurrently. In the first experiment time budgets (time spent walking, grazing, lying down, drinking water and browsing) of the cows and heifers were monitored for two consecutive days once a month, while in the second experiment blood samples were collected from the coccygeal vein once a month during weighing. Body condition scores were also determined during weighing times. Heifers maintained significantly (p0.05) of both blood urea nitrogen (BUN) (7.5±0.39 mmol/l) and TP (80.7±1.19 g/l) in November. All the animals had the least BUN levels in January (1.93±0.18 mmol/l) while the highest total protein (TP) (82.1±1.08 g/l) was recorded in February. All the animals showed distinct (p0.05) in most behavioural attributes in the cool-wet season. Heifers spent significantly (p0.05) body condition scores, amount of time spent browsing and drinking water. On the other hand, heifers (14.7±1.50%) and first parity cows (13.9±1.50%) traded-off most (p<0,05) of their time walking during the cool-dry season. Similarly heifers spent more time browsing (6.4±0.62%) forage plants (p<0.05) than all the cows during the cool-wet season. Grazing (r = 0.17) and standing (r = -0.18) were correlated (p<0.05) with all the behavioural attributes measured in this environment. It was concluded that seasonal dynamics in trade-off behaviour through time budgeting, maintenance of BUN and TP were necessary for the Nguni cows and heifers to maintain their body condition scores within a narrow range throughout the four seasons.

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