South African Journal of Animal Science
Not a member yet
46 research outputs found
Sort by
The farm-gate methane intensity and blue water footprint of nine diverse beef cattle breeds in South Africa
Get PDFA simulation study was done to estimate the methane intensity and blue water footprint of a weaner calf production system in South Africa. Nine genotypes, representative of indigenous, British, Zebu, and European breeds, were chosen based on their relative numbers and the availability of data. A farm of 1200 ha with a carrying capacity of 6 ha/large stock unit (LSU), which could thus carry 200 LSU in total, was simulated. The enteric methane emission of an LSU was estimated to be 94 kg of methane/year (tier 2), implying that 18 800 kg of methane was produced per year by the farm (200 LSU × 94 kg of methane). Likewise, the litres of blue water consumed on the farm was 3285 kilolitres (200 LSU × 16 425 litres/year/LSU). The methane intensity (kg methane/kg live weight) was calculated by dividing the annual methane emissions of the farm by the total kilograms of live weight leaving the farm. The blue water footprint was estimated similarly. The total live weight leaving the farm was calculated by combining the total kilograms of saleable calves and the total kilograms of culled cows sold. The Afrikaner, Bonsmara, Angus, Brahman, and Brangus breeds had low methane intensities and blue water footprints, while the European breeds had high values. The methane intensity varied from 0.59 kg of methane to 0.85 kg of methane, a 44% difference. The water footprint varied from approximately 100 to 150 L/kg live weight leaving the farm. More research is needed to validate these differences.
(Submitted 17 September 2024; Accepted 2 June 2025; Published 18 August 2025
Bibliometric insights into the South African Journal of Animal Science: Trends and contributions
Get PDFArticles (1558 in total) published in the South African Journal of Animal Science (SAJAS) were identified in the Scopus, Scielo, and InCites (Web of Science) databases. The Scimago Journal Rank (SJR) indicator for SAJAS in 2022 was 0.33, with a journal H-index of 37. The journal is in the Q3 quartile, reaching Q2 in 2014 and 2017, and has the 2nd highest SJR in African Animal Science and Zoology journals. The InCites average Category Normalised Citation Index is 0.43, with 77% of articles being cited, but varies between research fields, with a score of 0.32 for Agriculture, Environment, and Ecology (85% of published papers), 0.23 for Clinical and Life Sciences (14% of published papers), and 0.44 for Social Sciences. There is a mean of 43 references per article, with each article receiving, on average, 1.1 citations. Most papers are on poultry and ruminants, with fewer papers on wild animals and less prominent farm species. The major breeds studied include Merino sheep and Holstein cattle, with fewer papers on South African breeds. This analysis is important for the journal and its readership as a self-evaluation of the scope and impact of the journal and how this is changing, as well as aiding editors in shaping the journal’s future direction. Citations have decreased over the last 20 years, and international collaborations are few; however, bias in this analysis should be noted, as recent papers and papers not indexed in Scopus have lower numbers of citations. The journal must reaffirm itself as a leading journal for tropical animal production.
Submitted 13 May 2025; Accepted 23 May 2025; Published 16 June 202
Body conformation and weight relationships in Dohne Merino sheep: A comparison of measured and subjective traits
Get PDFThe morphometric and type traits of 269 Dohne Merino ram lambs were measured and/or assessed at four, eight, and 12 months of age. Body conformation scores were also awarded independently by three judges at each age. Estimated phenotypic correlations between conformation traits and body weights were significant for most of the measured morphometric traits and body conformation scores but not for the subjectively evaluated traits. Four principal components that accounted for all of the total variances were extracted for each age. Principal component one was more related to traits describing general body size, whereas principal component two was determined by traits describing the body heights of the sheep. In the stepwise regression of the effects of individual conformation traits on body weight, heart girth and body length explained the most variance in body weight at all three ages. Considerable variation between judges was found in the traits contributing most to the body conformation score. At four months of age, the only trait of importance common to all three judges was heart girth, while at eight months of age, conformation of the head, shoulder width, and body condition score were the most important traits. At 12 months of age, body length was the most important trait for all three judges, when assessing body conformation score. The three judges clearly emphasised different traits when assessing body conformation and awarding classification symbols. This would lead to different sires being eligible for selection at different studs, potentially hindering selection progress in the breed.
Submitted 25 October 2021; Accepted 27 May 2025; Published 17 June 2025
-------------------------------------------------------------------
Significance of research to South African science
The article “Body conformation and weight relationships in Angora goats” by Snyman et al. (2025) provides valuable insights for South African animal science, particularly in the optimisation of breeding strategies for Angora goats. As South Africa is the world’s largest producer of mohair, understanding the relationships between body measurements and live weight is essential for improving animal selection, fibre yield, and overall productivity. This study offers practical tools for farmers to estimate body weight through accessible morphological indicators, especially in resource-limited settings without weighing facilities. The findings support more informed decision-making in genetic improvement programmes and contribute to the sustainability and profitability of the country\u27s mohair industry
Short communication: Effects of polyethylene glycol treatment on the chemical composition and in vitro dry matter degradability of Searsia lancea leaves
Get PDFThis study investigated the effects of incremental levels of polyethylene glycol (PEG) treatment on the chemical composition and in vitro dry matter degradability (IVDMD) of Searsia lancea leaves. Polyethylene glycol was sprayed onto S. lancea leaves at 0, 5, 10, 15, and 20 g/kg of dry matter (DM). Data were analysed using a one-way analysis of variance, while linear and quadratic responses were analysed using polynomial regression analysis. There were negative linear and quadratic effects on the crude protein (CP), neutral detergent fibre (NDF), total phenolic (TP), total tannin (TT), and condensed tannin (CT) concentrations in response to the incremental levels of PEG. Treatment with 20 g PEG/kg DM produced the lowest ether extract (EE), NDF, TP, TT, and CT concentrations. Magnesium showed a negative linear response to incremental levels of PEG, and treatment with 10 g PEG/kg DM produced the highest potassium, sodium, and sulphur concentrations. In vitro DM degradability at 36 hours showed a positive linear response to increasing levels of PEG, and 20 g PEG/kg DM resulted in the highest IVDMD. In conclusion, treating S. lancea leaves with incremental levels of PEG reduced the concentrations of CP, EE, NDF, TP, TT, and CT, while enhancing the IVDMD. Our results suggest that treatment with PEG at 20 g/kg may be most suitable for improving the nutritive value of S. lancea.
(Submitted 2 March 2025; Accepted 17 September 2025; Published 13 October 2025
Possible factors affecting the bioavailability of copper and the copper requirements of wild, free-ranging African herbivores: A review
Get PDFFree-ranging wild herbivores in Africa comprise 78 species of ruminants and several species of monogastric hindgut fermenters, and are classified as grazers, mixed feeders, and browsers. The objective of this review is to provide guidance to wildlife nutrition advisers by outlining key metabolic principles relevant to assessing copper nutrition in herbivores. In domestic species, copper bioavailability is influenced by dietary copper antagonists, copper solubility at absorption sites, and the homeostatic regulation of copper metabolism. Differences in the homeostatic control of copper absorption and metabolism in the liver between ruminants and monogastric species have a major effect on their tolerance to excessive copper exposure. As some elements in the diet are antagonistic to copper solubility in the digestive tract, dietary copper concentration alone has limited diagnostic value for assessing the potential copper nutrition status of a ruminant. Dietary copper is most soluble in acidic environments and factors influencing rumen pH, such as the effect of diet type on rumination and saliva flow, could thus influence copper solubility. In monogastric species, the solubility of dietary copper in the stomach can be high (up to 80% in vitro) because of the acidic environment of the stomach. Consequently, in domestic species, the bioavailability of copper varies from 1% to 10% in mature ruminants, compared with an estimated ≥30% for non-ruminants. This suggests that for wild species with similar body weights and diets, dietary copper requirements per kilogram of feed intake for maintenance should be substantially lower for monogastric species than for ruminants.
(Submitted 22 June 2025; Accepted 30 August 2025; Published 12 November 2025
Effect of propolis supplementation on haematological and biochemical parameters in lambs
Get PDFThis study evaluated the effects of oral propolis supplementation on haematological and metabolic indicators and coagulation parameters in neonatal lambs. Forty healthy newborn lambs were randomly assigned to either a control group or a treatment group receiving 1.5 mL of propolis extract daily for 15 days. Blood samples were collected on days 0, 7, 21, and 45 to assess for changes over time. The results showed that propolis did not cause any harmful effects on liver or kidney function, and all blood parameters remained within normal physiological ranges. Although most changes in biochemical markers were time-related, lambs supplemented with propolis showed slight improvements in lipid metabolism, including numerically lower cholesterol and triglyceride levels at specific time points. Moreover, lambs in the propolis group tended to gain more weight over time, suggesting possible benefits for early growth. Minor differences were observed in some clotting parameters, but no adverse effects on blood coagulation were detected. These preliminary findings suggest that propolis may be considered a complementary strategy in lamb production, although further studies are needed to confirm its long-term benefits. Propolis-use may help facilitate a reduction in the use of synthetic additives in small ruminant production systems.
(Submitted 21 July 2025; Accepted 12 September 2025; Published 30 September 2025