Research Articles (Animal and Wildlife Sciences)
Permanent URI for this collectionhttp://hdl.handle.net/2263/1748
This collection contains some of the full text peer-reviewed/ refereed articles published by researchers from the Department of Animal and Wildlife Sciences
Browse
Recent Submissions
Now showing 1 - 20 of 464
Item Brainstem auditory evoked responses : objective hearing threshold assessment in Holstein cows(AOSIS, 2024-10-21) Naudé, Alida Maryna; Erasmus, Lize-Mari; De Swardt, Liesl; Bornman, Juan; Van Marle-Koster, EsteBACKGROUND : Animal audiology utilizes brainstem auditory evoked responses (BAER) as a non-invasive tool to assess hearing in animals, including Holstein dairy cows. Understanding cows’ auditory capabilities is critical for their welfare, especially given their exposure to farm noise. OBJECTIVES : This study provides preliminary normative BAER data for Holstein cows by focusing on absolute and interpeak wave latencies. The objective is to assess the impact of farm noise and expand audiologists’ practice scope. METHOD : Ten Holstein cows were tested using monoaural broadband click stimuli with contralateral masking. Earphones with foam ear tips were used to minimize environmental noise interference. The BAER responses were recorded via subdermal needle electrodes placed at standardized locations on the cows’ heads. The data were analysed using descriptive statistics to determine auditory thresholds and wave latencies. RESULTS : The cows exhibited auditory thresholds at 90 dB SPL (55 dB nHL). Detailed wave and interpeak latencies were recorded at intensities from 85 to 105 dB SPL. At 90 dB SPL, the average latency for wave V was 5.17 ms, marking the auditory threshold for Holstein cows. CONCLUSION : These findings provide key insights into the auditory sensitivity of Holstein cows, highlighting BAER’s potential for monitoring auditory health and evaluating the effects of noise pollution on animal welfare. This research underscores the value of integrating animal audiology into the audiologist’s scope, ultimately enhancing both animal welfare and farming sustainability. CONTRIBUTION : This study adds to the limited literature on farm animal auditory health and suggests strategies to improve welfare through better auditory management.Item Thermal profiles associated with nest site selection of Nile crocodiles (Crocodylus niloticus) on a commercial crocodile farm(Elsevier, 2025-07) Viljoen, Devon Marie; Webb, E.C. (Edward Cottington); Myburgh, Jan G.; Truter, Johannes Christoff; Van Wyk, Hannes; Myburgh, Albert; u10120263@tuks.co.zaUnderstanding crocodile nest site selection is important in the context of climate change and related habitat alterations. This study assessed a current nesting environment on a crocodile farm in South Africa, examining associations between various nest site selection parameters, with a particular emphasis on the role of temperature. It was hypothesized that thermal profiles of nests and factors affecting nest temperatures (orientation, shading, grassy cover) would directly impact nest site selections, nests closer to waterbodies would be preferred, dominant females would dictate nesting area use, and human presence would not impact nesting behaviours as farmed crocodiles are accustomed to this. Nile crocodiles in this study produced nests of similar depth to wild Nile crocodiles, and subsurface temperatures varied with nesting layouts (section, orientation, shading), climate factors, and grass growth. Although a complex interaction of factors affected nest site selections, mean subsurface nest temperatures tended to fit into the narrow range of 25–26 °C, highlighting a measure of stability within the nesting environment. Daily temperatures and temperature ranges did however vary significantly between crocodile-selected nesting depths. Behaviour played an important role in the nest site selections, highlighting how nesting sites must be more than just thermally viable in farmed settings. Grassy growth over nesting sites reduced the surface and subsurface temperatures of those nests. Although this did not affect nesting site occupancy, crocodiles selected against depositing eggs in these sites. Nests closer to waterbodies and tourist walkway were occupied more frequently; however, successful nesting occurred further from the walkway. The size (snout-hindlimb length) of crocodiles within nesting sites did not correlate to preferred nesting sections within the pen. Further research is needed to determine if thermally optimal nesting conditions might be complicated by climate change related nesting environment alterations on commercial farms. HIGHLIGHTS • Nest site selections were assessed using drones and iButtons on a crocodile farm. • Temperatures varied significantly between crocodile-selected nesting depths. • Mean subsurface nest temperatures tended to fit into the range of 25–26 °C. • Crocodiles selected against depositing eggs in cooler, grass-covered nests. • Crocodiles deposited eggs in nest sites further away from a tourist walkway.Item Factors affecting in vitro oocyte maturation in Southern white rhinoceros (Ceratotherium simum simum)(Medpharm Publications, 2025-05) Smuts, Mario P.; De Bruin, P.R.; Fosgate, Geoffrey Theodore; Vorster, L.; De la Rey, Marlene; Lichtenberg, C.; Young, C.; Durrant, B.S.; Meyer, Leith Carl Rodney; Holm, Dietmar Erik; mario.smuts@up.ac.zaBACKGROUND : Population numbers of free-roaming rhinoceros are dwindling while natural breeding in captive populations is challenged by sub-optimal fertility. When natural breeding programmes fail and population numbers continue to decline, the use of assisted reproduction technologies (ART) as a conservation tool to save wildlife species from extinction is imperative. Assisted breeding programmes in rhinoceros are challenging and attempts to develop species-specific ART beyond artificial insemination have been limited. This study evaluates various ex- and in-situ factors that could potentially affect in vitro oocyte maturation (IVM) in the Southern white rhinoceros (SWR). OBJECTIVES : To identify predictors of oocyte maturation following ovum pick-up (OPU) procedures performed on a large number of rhinoceros under different management conditions. METHODS : Data from 85 OPU procedures between November 2018 and June 2023 were obtained for this study. A total of 23 factors (three animal, four environmental, 16 laboratory) were evaluated as potentially affecting IVM success. RESULTS : Of the 85 procedures performed on 59 SWR, a total of 265 oocytes were collected with a median of two oocytes (range 0–18) per OPU. Eighteen (18) of the procedures yielded 0 oocytes. The overall maturation rate was 30% (80/265), and six identified factors had significant univariate associations with maturation outcome, of which three remained in the multivariable model. CONCLUSION : Farming system, season and oocyte density in maturation medium (> 100 ul/oocyte) were independently associated with improved maturation success (p < 0.05).Item The effect of ecotype and year on the production and reproductive performance of Nguni cows in the Limpopo Province of South Africa(South African Society for Animal Science, 2025) Mulaudzi, Mmboniseni; Webb, E.C. (Edward Cottington); Mashiloane, Majela L.; edward.webb@up.ac.zaThis study investigated the effects of Nguni cattle ecotype and year on the production and reproductive performance of cows in the Limpopo Province of South Africa. Production data for 471 calvings (142 Venda, 65 Shangaan, and 264 Pedi ecotype Nguni cows) at Mara Research Station were analysed to determine the differences between years and ecotypes in birthweight, weaning weight, days-to- reconception, inter-calving period, weight of cow at breeding and at weaning, and weaning efficiency. The effects of ecotype and year on the production and reproduction parameters were analysed using the SAS® mixed models procedure. Cows of the Shangaan ecotype were the smallest in size, while the Venda ecotype was both heavy and short, and gave birth to calves with lower birthweights and higher weaning weights. Ecotype did not affect the inter-calving period and days-to-reconception, but influenced weaning efficiency and weight-related reproduction traits. Year influenced the birth and weaning weights, with years with high precipitation also having high production efficiencies. The smaller-framed Shangaan ecotype had a better weaning efficiency, days-to-reconception, and inter-calving period than the Pedi and Venda ecotypes in the year with the lowest precipitation (2011). No year effects were observed for days-to-reconception, but the inter-calving period, weaning efficiency, and weight-related reproductive traits were affected by year. Ecotype and year thus both influenced the production and reproduction traits of Nguni cattleItem Tannin extract dietary thresholds for preventing unacceptable suppression in intake, digestibility, and growth in sheep and cattle : a meta-analysis(South African Society for Animal Science, 2025) Ahmed, Osman Merghani Makki; Hassen, Abubeker; Lehloenya, Khoboso Christina; abubeker.hassen@up.ac.zaThis meta-analysis aimed to identify the optimal inclusion and threshold levels for black wattle, quebracho, and chestnut tannin extracts (TE) in sheep and cattle, in terms of their effects on dry matter intake (DMI), digestibility, weight gain, and nitrogen balance. Data were compiled from 44 scientific publications, representing 580 sheep and 742 cattle. The percentage change approach was used to quantify responses to TE inclusion. Mixed model analysis was performed to evaluate piecewise and linear regressions, with scientific publications treated as random effects, and TE level, TE source, animal species, supplementation period, dietary fibre level, dietary protein level, and animal age as fixed effects. The piecewise model provided the best fit for all responses. The optimal inclusion level was established at a 0% response, while the threshold was established at a 5% reduction in performance. With no differences between TE sources, the optimal inclusion level for DMI was 1.5 g TE/100 g dry matter (DM) and threshold was 3 g TE/100 g DM in both sheep and cattle. Sheep were slightly more able to digest crude protein than cattle (3.89 ± 1.91%) at the same TE inclusion level, but no other differences were observed between the two species. Black wattle TE reduced organic matter digestibility (−4.95 ± 1.82%), neutral detergent fibre digestibility (−8.62% ± 4.07), and acid detergent fibre digestibility (−16.83 ± 6.06) responses, relative to chestnut TE. Moreover, TE inclusion (particularly black wattle TE) raised faecal nitrogen while lowering urinary nitrogen. These differences between TE sources did not significantly influence the weight gain response, with an optimal inclusion level of 1.5 g TE/100 g DM, and a threshold of 2.3 g TE/100 g DM.Item Heat stress in dairy cows : a review of abiotic and biotic factors, with reference to the subtropics(South African Society for Animal Science, 2025) Erasmus, Lize-Mari; Van Marle-Koster, Este; lizemari.erasmus@up.ac.zaHeat stress has been identified as one of the major challenges for livestock production. Global temperatures are steadily increasing, with South African temperatures increasing at nearly twice the global rate. Of the livestock used for food production, dairy cows are the most sensitive to thermal changes, which have detrimental effects on their health, welfare, and overall productivity. Several abiotic factors that influence the heat load experienced by the cow are not commonly included in thermal indices used to measure heat stress; these include solar radiation, wind speed, and soil quality. Furthermore, the thermal comfort zone of cows has been altered by years of intense selection for increased milk yield, causing cows to become heat stressed at lower temperatures. Considering the abiotic and biotic factors affecting the cow’s heat load, it can be argued that dairy cows in tropical and subtropical climates are experiencing constant heat stress. In this review, the abiotic and biotic factors influencing the heat load experienced by dairy cows are reviewed, along with the available thermal indices that can be utilised at farm level.Item Assessing extensive pasture-based beef production in South Africa under future climate change conditions(Elsevier, 2025-10) Magona, Christopher; Hassen, Abubeker; Tesfamariam, Eyob Habte; Mengistu, Michael; Visser, Carina; Oosting, Simon; Van der Linden, Aart; carina.visser@up.ac.zaCONTEXT : Assessing the impact of climate change on extensive pasture-based beef production across varied agro-ecological regions is crucial for designing customized adaptation measures. OBJECTIVE : This study assesses the effects of climate change on extensive pasture-based beef production systems in three South African agro-ecological regions (Bloemfontein, Phalaborwa and Buffalo Berlin) under two climate change scenarios, namely the representative concentration pathways (RCPs) 4.5 and 8.5. METHODS : The LiGAPS-Beef model, previously calibrated for the region, was used to evaluate the impact of climate change on beef cattle production under pasture-based extensive systems. Four breed types, namely Bos taurus, Composite, Zebu indicine and Sanga cattle were included in this study. Genetic parameters for each breed were obtained from SA Stud Book, Livestock Registering Federation (LRF) and literature. Measured historical weather data was obtained from the South African Weather Service for the three agro-ecological regions. An ensemble of eight regional climate model (RCA4) simulations from the CORDEX Africa initiative was used to generate future climate change projection data for the period 2036–2065 under RCP 4.5 and RCP 8.5 scenarios. The future nutritional composition data for forage was collected from studies that simulated and predicted future forage quality under climate change conditions. RESULTS AND CONCLUSION : The study found that the baseline average daily gain (ADG) was significantly higher (0.40 kg/head/day) than the simulated RCP 4.5 (0.21 kg/head/day, −48 %) and RCP 8.5 (0.20 kg/head/day, −51 %) ADGs regardless of breed type when both feed quality and feed quantity limited growth. Although the effect of the climate change scenarios on beef production was agro-ecological region dependent, the performance of Bos taurus declined more than other breeds under future climate scenarios while the Sanga and the Composite types were the most resilient, especially in hot climate areas. Model simulations predict that future climate change will have a greater negative impact on cattle in Buffalo Berlin and Phalaborwa, while those in Bloemfontein will be least affected. The study also highlights that under future climate change scenarios, pasture quality will be the key factor influencing cattle growth in Bloemfontein and Buffalo Berlin, while pasture quantity will be the dominant factor in Phalaborwa if stocking rates remain unchanged. The study highlights the need for nutritional and pasture management interventions for pasture-based extensive system (e.g., feed supplementation, adjusting the stocking rate to match pasture availability, identifying and integrating drought and/or heat tolerant ecotypes, fodder trees that provide shade for the animals) to mitigate the expected decline in beef cattle performance in South African agro-ecological regions. SIGNIFICANCE : Quantifying the impact of anticipated climate change on pasture-based extensive beef production and identifying specific factors that limit beef production per breed type in the different agro-ecological regions is crucial for assessing the potential ramifications on beef production. This information empowers farmers and policy makers to develop targeted mitigation and adaptation strategies that promote resilience of the beef production system in the respective regions. HIGHLIGHTS • Quantifying climate change impact on beef production is vital for coping measures. • Beef cattle growth was simulated under RCP 4.5 and RCP 8.5 in South Africa. • 2050 simulated growth declined by 48 % in RCP 4.5 and 51 % in RCP 8.5 from baseline. • Growth of Bos taurus was most adversely affected, but Sanga was the most resilient. • Location-specific intervention is vital to sustain beef production in South Africa.Item Nutrient value and density of South African processed meat(Elsevier, 2025-07) Pretorius, Beulah; Muller, Carmen; Schonfeldt, H.C. (Hettie Carina); beulah.pretorius@up.ac.zaThere has been a significant rise in processed meat consumption in South Africa, yet no previous studies have assessed the nutrient density of country-specific processed meats. This study analysed eight processed meat products: tinned corned beef, tinned meatballs, hamburger patties, frozen beef sausages, French and chicken polony, red and chicken viennas, focusing on their nutrient density and nutrient-to-price ratio. The energy content varied from 447 kJ/100 g to 1020 kJ/100 g in tinned meatballs and frozen beef sausages, respectively. Protein content ranged from 8.31 g/100 g in tinned meatballs to 15.9 g/100 g in hamburger patties, lower than in red meat. Fat content was 3.69 g/100 g in tinned meatballs to 17.9 g/100 g in frozen products. Saturated fat constituted 30–50 % of total fat, monounsaturated fat 35–47 %, and polyunsaturated fat 3–25 %. Trans-fat levels were within regulatory limits. Iron content was highest in corned beef at 3.61 mg/100 g, and zinc was highest in hamburger patties at 2.86 mg/100 g. Over 80 % of products met sodium reduction targets. Nutrient profiling indicated tinned meatballs, French polony, and hamburger patties offer the best nutritional value per cost. Processed meats can provide protein, iron, and zinc, but consumer education on the benefits of lean meats and moderate processed meat consumption remains important.Item Implication of dietary barberry (Berberis Vulgaris) leaves inclusion on growth performance, nutrient digestibility, and carcass traits in ostriches(Nature Research, 2024-10-20) Afshin, Mojtaba; Afzali, Nazar; Hosseini-Vashan, Seyyed Javad; Hajibabaei, Ali; Ghavipanje, Navid; Vargas-Bello-Perez, EinarThis study determined production performance, nutrient intake, digestibility, and carcass traits from ostrich chicks fed with barberry (Berberis Vulgaris) leaves (BVL) as a replacement for alfalfa hay (AH). For 150 days, 30 male ostrich (Struthio camelus) (9.10 ± 0.89 kg live weight, mean ± SD) were randomly grouped into five dietary BVL inclusion levels to replace AH: a control diet based on 100% AH (CTRL), and four groups with BVL as a substitute for AH at varying levels including 25% (BVL25), 50% (BVL50), 75% (BVL75), and 100% (BVL100). The average daily feed intakes (ADFI) were recorded and birds were weighed monthly. The nutrient intake and digestibility were measured for the following final 5 days of the trial. The ADFI was higher (p = 0.025) for BVL100 and BVL75 than for CTRL. Ostriches fed on BVL50 had the highest average daily gain (ADG, p = 0.025) and the lowest feed conversation ratio (FCR, p = 0.0001). Return per kg BW gain was also enhanced (p = 0.018) with BVL50 feeding. Dietary BVL levels did not affect the digestibility of OM (p = 0.257), CP (p = 0.260), EE (p = 0.610), CF (p = 0.427), and Ash (p = 0.461). Also, there were no changes in AME (p = 0.180) or AMEn (p = 0.670). The hot carcass weight (HCW, p = 0.331) and dressing BW (p = 0.237) were not affected. Overall, the results suggest that BVL can replace AH in ostrich diets without deleterious impact on performance, however, its partial substitution (for 50% AH of diet) has been associated with improved ADG, FCR, and reduced feeding costs.Item The effects of postnatal exposure to di-n-butyl phthalate (DBP) on the male reproductive system in animals : a systematic review and meta-analysis(Elsevier, 2025-06) Ibrahim, Mohammed I.A.; Ahmed, Osman Merghani Makki; Botha, C.J. (Christo J.); u17372098@tuks.co.zaDi-n-butyl phthalate (DBP) is a ubiquitous environmental contaminant widely used in personal care products and medical products, causing male reproductive toxicity in humans and animals following exposure. It has endocrine-disruptive activities, causing adverse effects on the male reproductive system. This study aimed to investigate the male reproductive injury induced by DBP in animals. We conducted a systematic review and meta-analysis of the related literature captured in Google Scholar, MEDLINE, Scopus, PubMed and Web of Sciences databases. This review included animal studies that were postnatally exposed to DBP. After applying the inclusion and exclusion criteria, a total of 48 relevant studies were selected, which included studies in rats (n = 29), mice (n = 5), rabbits (n = 3), birds (n = 6), and fish (n = 5) exposed to DBP. The scope of the study included testicular and epididymal morphology, sperm quality and oxidative stress parameters, steroidogenic enzymes, and sex steroid hormones. The meta-analysis focused on rat studies, which revealed a significant decrease in sperm count (p < 0.001), sperm motility (p < 0.001), superoxide dismutase (SOD, p < 0.001) activity and testosterone (p < 0.001) concentration. Moreover, DBP exposure significantly increased sperm abnormality (p < 0.001), catalase (CAT; p = 0.003) activity and malondialdehyde (MDA; p < 0.001) levels. Postnatal exposure to 1 mg/kg DBP could decrease the sperm count, sperm motility, testosterone concentration, and SOD activity by 5.87 %, 0.17, 7.46 % and 21.38 %, respectively. As a result of the meta-analysis, SOD activity was more sensitive to DBP following postnatal exposure than CAT activity or MDA levels, while sperm abnormality was less susceptible than sperm count and sperm motility to DBP exposure. Generally, the systematic review and meta-analysis demonstrated that postnatal exposure to DBP-induced male reproductive injury by inducing oxidative stress and altering steroidogenesis, and sex hormones in animals. Moreover, the review identified important gaps in animal studies of dermal exposure to DBP, emphasizing the need for further research to assist in conducting more rigorous epidemiological and risk assessment studies that represent real-life exposure scenarios.Item Sustainable utilization of wild fruits and respective tree byproducts as partial feed ingredients or supplements in livestock rations(Frontiers Media, 2025-03) Chisoro, Prince; Mazizi, Bulelani; Jaja, Ishmael Festus; Assan, Never; Nkukwana, Thobela T.The long-term survival of livestock production systems depends critically on the sustainable usage of resource-efficient strategies, such as the supplementation or replacement of conventional feed ingredients (CFI) like maize and soybean with less expensive, more effective, and locally accessible sources. Wild fruits and their byproducts (WFBP) from multipurpose trees (e.g. leaves, seeds) offer a promising low-cost non-traditional alternative dietary source of energy, protein, vitamins, minerals, oxycaretenoids, and bioactive substances that function at a cellular level in livestock. According to research these non-CFI can enhance livestock voluntary intake, digestibility, and overall performance while alleviating the heavy reliance on CFI. Conversely, the use of these alternative feed resources (AFR) necessitates a thorough evaluation of their nutrient composition, antinutritional factors (ANF), and proper inclusion levels. At low appropriate inclusion levels in livestock rations, the availability of optimal crude energy, crude protein content, and availability of necessary amino acids (AA) in these AFR, can be taken advantage of in saving costs and reducing demands for soybean and maize, which are the indisputable CFI for both livestock and man. This review synthesizes the current research status of WFBP looking at their nutritional profiles (energy, protein, minerals, fiber etc.) and their impacts in livestock productivity. Furthermore, this review will address potential processing techniques to lessen their drawbacks like ANF or palatability. By highlighting these issues, this paper seeks to provide a guide for the sustainable incorporation of these AFR into livestock diets, striking a balance between nutritional effectiveness and economic feasibility. HIGHLIGHTS ● Global livestock production is facing one major challenge of ensuring adequate availability of nutritious feed. ● Due to the growing demand for meat and animal products, there is a need to design new alternative efficient feed systems. ● This review article details the possible use of wild fruits and their respective tree byproducts (WFBP) as partial or supplement stockfeed ingredients. ● The knowledge base of these potential alternative feedstuffs and their limitations are highlighted in this review.Item Gendered impacts of climate change on integrated crop-dairy goat farming in Kenya(Frontiers Media, 2025-03) Cheboi, Juliana Jepkemoi; Nkukwana, Thobela T.; Greathead, Henry; Keyster, MarshallAgriculture is the economic engine of Kenyan economy since it contributes to about 24% of the real GDP. However, its contribution has significantly reduced due to climate change that has impacted negatively crop production, pasture, and animals. A cross-sectional survey was undertaken among 201 households in Endo ward, Elgeyo Marakwet County to understand the effects of climate change and feed diversity. Climate change has profoundly affected individuals along the integrated value chain, with unreliable rainfall being the most significant issue, reported by 99.5% of respondents. Contrastingly, floods during the rainy season were experienced by 15.9%, while pests and diseases were reported by only 1.5% of respondents. The findings highlight a significant gender disparity in the impact of climate change along the integrated value chain resulting in shifts and challenges that impact women, men, and youth in distinct ways. Women, particularly those over 35 years, face severe consequences such as food shortages and malnutrition (56.2%), and loss of lives due to environmental disasters (39.8%). Young females bear increased domestic responsibilities, including fetching water (86.6%), which intensifies during periods of climate stress. Men over 35 years reported substantial economic losses and the impact on agricultural productivity due to pests and diseases. Although younger males are affected, their experiences are less severe compared to older males and females. In the context of dairy goat farming, there is a gender-based specialization of tasks. Men over 35 years predominantly handle activities such as shed construction (60%), marketing (54.2%), pest and disease control (57.2%), enterprise decision-making (58.7%), breeding (58.7%), and slaughtering (64.7%). Younger males, those under 35 years, are primarily responsible for transportation (62.2%). On the other hand, women under 35 are actively involved in feeding the goats (62.7%), cleaning the sheds (57.7%), and providing water (56.7%), with a notable focus on this younger age group of women. The study underscores the need for gender-sensitive adaptation strategies to address the differentiated impacts of climate change. By understanding the specific challenges faced by various demographic groups, policymakers and development practitioners can design more effective interventions to build resilience, and ensure equitable outcomes along the integrated farming system.Item Shifting the focus from animal species to livestock production systems : an interactive tool for evaluating food contributions relative to environmental impacts(Oxford University Press, 2025-02) De Lange, Elna; Du Toit, Cornelius Jacobus Lindeque; Fletcher, Andrew; Iliushyk, Taras; Kalinovska, Bohdana; Lupton, Naomi; Maree, Enrike; Ederer, PeerIMPLICATIONS : The Animal Production System Evaluator tool for evaluating and comparing livestock production systems illustrates the contribution they can make to nationally adjusted protein food baskets in relation to different environmental impact indicators. There is value in creating interactive tools for stakeholders, which facilitate informed decision-making in order to optimize productivity and sustainability in livestock production. The Animal Production System Evaluator tool builds on data sources from the Food and Agriculture Organization, the Global Livestock Environmental Assessment Model, and the PLANET Food System Explorer. The tool aims to satisfy the following characteristics: Multifaceted Assessment: Evaluations of livestock production systems are required for integrating both nutritional contributions and environmental impacts to promote sustainable practices. Tailored Solutions: Region-specific solutions that account for the diverse conditions across different areas are needed, moving away from a one-size-fits-all approach. Systemic Focus: It is important to focus on entire production systems, rather than on animals, to ensure effective resource management and to mitigate environmental impacts. Global Relevance: Livestock production’s dual role in providing nutrients and managing environmental impacts is essential for achieving sustainable development goals.Item Ruminant livestock farmers and industry are leading innovation to deliver human nutrition and improved environmental outcomes through sector lifecycle collaboration : a review of case studies(Oxford University Press, 2025-02) Maree, Enrike; Blignaut, James; Gilliland, John; Lee, Michael R.F.; Manzano, Pablo; McCosker, Terry; Du Toit,; Du Toit, Cornelius Jacobus Lindeque; Truter, Wayne; Weinheimer, Ben; Polkinghorne, RodIMPLICATIONS : Well-managed systems like adaptive grazing and silvopasture enhance soil health, biodiversity, and water retention while reducing greenhouse gas emissions. Intensive feeding practices, from supplementation to feedlots, increase meat production and manage emissions effectively through controlled feeding and manure strategies. Combining sustainable grazing with intensive systems balances land use, nutrition, and emissions reduction, addressing global food demand. Livestock’s up-cycling efficiency converts inedible grasses and by-products into nutrient-dense food, critical for food security. Farmers and industry leaders, through innovation and life-cycle analysis, use data-driven decisions to optimize sustainability, showcasing livestock’s essential role in achieving environmental and nutritional goals in agriculture.Item Effect of Vachellia tortilis leaf meal and sunflower oil Inclusion in supplementary diets of lambs on in vitro short-chain fatty acid and gas production and in vivo growth performance(MDPI, 2025-03) Serumula, Mahlogonolo Daniel; Pepeta, Bulelani Nangamso; Moyo, Mehluli; Suinyuy, Terence Nkwanwir; Nsahlai, Ignatius VerlaThis study examined the effect of dietary Vachellia tortilis leaf meal and sunflower oil inclusion in supplementary diets on in vitro short-chain fatty acid (SCFA) and gas production and the in vivo growth performance of lambs. Four concentrate dietary treatments comprising control (CL), Vachellia tortilis leaf meal (VT), sunflower oil (SFO), and Vachellia tortilis leaf meal sunflower oil (VSFO) were formulated. Eight Merino lambs were blocked into two live weight blocks where animals within each block were randomly assigned to dietary treatments, making two animals per treatment. Lambs were offered a concentrate diet of 480 g/day per head, with urea-treated hay fed as a basal diet. Dietary effects were evaluated for in vitro short-chain fatty acid and gas production and 28-day growth performance of lambs over three study periods. The inclusion of VT and SFO showed no statistically significant effect on total SCFAs, acetate to propionate (A:P) ratio, methane (CH4), and carbon dioxide (CO2) production (p > 0.05), which might be attributable to low experimental units. The hourly A:P ratio and CH4 yield were the highest (p < 0.05) at 16 h of incubation. The inclusion of VT showed no statistically significant effect on growth performance and gas production due to the small sample size. Therefore, VT can be explored as a supplementary protein source in lamb diets given the impression of not showing any causative adverse effects on growth performance and in vitro gas production, although further research with larger sample sizes is needed to confirm these findings.Item Calcium and phosphorus digestibility in broilers as affected by varying phytate concentrations from corn(Elsevier, 2024-11) Venter, Kyle M.; Li, W.; Angel, R.; Plumstead, P.W.; Proszkowiec-Weglarz, M.; Enting, H.; Ellestad, L.E.Dietary phytate P (PP) concentration impacts Ca and P digestibility in broilers. Research was conducted to determine the impact of increasing concentration of dietary PP, with and without phytase, on broiler standardized ileal digestibility (SID) of Ca and P. Digestible (Dig) Ca and P were calculated by multiplying SID and the analyzed dietary Ca and P concentrations. The experiment was a factorial arrangement of 2 phytase (0 and 1,000 U/kg) and 4 PP (0.16, 0.23, 0.29, and 0.34%) concentrations. Treatments were fed for 36 h from 20 to 22 d of age (4 b/pen, n ≥ 7 replicate pens/treatment). Different ratios of corn and corn germ were used to achieve the desired PP concentrations. A limestone with 800 µm geometric mean diameter was used as the sole Ca source to achieve 0.7% Ca in the final diets (96% Ca from limestone). An additional diet was fed that was N, Ca- and P-free, for the determination of endogenous losses of each nutrient. Distal ileal digesta were pooled from all birds in a pen. There were no interactions between PP and phytase on SID Ca or Dig Ca from limestone. Irrespective of phytase inclusion, increasing PP from 0.16 to 0.34% decreased SID Ca from 53.8 to 38.1% (P < 0.05). The SID Ca averaged 41.5 and 51.4% in diets containing 0 and 1000 U phytase/kg, respectively, across all PP concentrations (P < 0.05). Interactions were seen between PP and phytase on SID and Dig P (P < 0.05) with SID P of 31.1, 24.0, 20.1, and 16.3% for broilers fed 0.16, 0.23, 0.29, and 0.34% PP diets without phytase, respectively. When phytase was included at 1000 U/kg, SID P was 89.9, 87.5, 73.9 and 60.4% for diets containing 0.16, 0.23, 0.29 and 0.34% PP, respectively (P < 0.05). Overall, phytase improved SID Ca and P independent of PP concentration. However, with increasing PP concentration, both SID Ca and P were negatively affected.Item Digestible calcium in broiler production(Plaas Media, 2025-01) Jacobs, Kean; u19167424@tuks.co.zaThe broiler industry is facing a severe problem related to the increased incidence of skeletal abnormalities. This not only raises concerns for animal health and welfare, but impacts growth performance and subsequently broiler operation profitability.Item Behaviour of commercial layer hens in enriched cages and floor systems examined using human and video-based observations(South African Society for Animal Science, 2025-06) Chilemba, Timothy.; Van Marle-Koster, Este; Masenge, Andries; Cromhout, M.; Nkukwana, Thobela T.; evm.koster@up.ac.zaThere is considerable pressure to eliminate the use of conventional cages in commercial layer hen production systems. However, the assessment of alternative systems that can ensure the hen's ability to perform natural behaviours, while simultaneously enhancing farm productivity and economic efficiency, remains incomplete. This study assessed layer behaviour in a floor system and in enriched cages on a commercial layer farm using human and video-based observations. The study focused on dust bathing, nesting, feather pecking, and perching behaviours, and on the formation of mud balls on the feet. A large proportion (72.9%) of the hens exhibited dust-bathing behaviour, with an average duration of 22.63 minutes. Feather pecking was exhibited by 35.4% of layers in the enriched cages, compared to 58.3% of layers in the floor system. Overall, feather pecking was the least observed behaviour. Layers in enriched cages used perches more (47%) than layers in the floor system (27%), and a negative association was found between body weight and perching in layers in the floor system. At the end of the six-week trial period, 41.67% of the hens had developed mud balls on their toes that exceeded 3 cm in length. The results of this study provide evidence of the relationships between poultry behaviour, welfare, and production. Video-based observations confirmed that farm managers may not be able to identify certain welfare-related behavioural aspects unless they are closely monitored. The results of this study may be used to inform stakeholders about behaviour and welfare considerations in the management of commercial layers.Item Implementation of a digestible calcium system : why is it needed and where are we?(Elsevier, 2025-06) Venter, Kyle M.; Angel, R.; Korver, D.R.; Cunha, M.; Plumstead, P.W.The regulation of blood calcium (Ca) and phosphorus (P) levels are closely intertwined, requiring that their metabolically available supply in the diet be carefully balanced. The majority of the P in plant-based feed ingredients is stored as phytate, which is poorly digestible by broilers, while inorganic P sources also show significant variability in digestibility. For decades, poultry nutritionists have incorporated available P in diet formulation, recognizing that the digestibility of P in feedstuffs is highly variable. In contrast, poultry diets are still formulated on a total Ca (tCa) basis, overlooking the variable digestibility of Ca from different dietary sources. Incorrect assumptions regarding the digestibility of Ca can lead to Ca imbalances, which negatively affect both broiler health and overall performance. Furthermore, the influence of Ca and limestone on phytase efficacy, which plays a critical role in enhancing P availability by breaking down phytate, is highlighted. As the poultry industry moves towards implementing a digestible Ca (dCa) system, the development of accurate prediction equations for limestone digestibility becomes essential. Such an approach not only improves the precision of diet formulation but also enhances overall broiler performance by ensuring a more balanced and metabolically available supply of both Ca and P. Transitioning to a dCa system, in conjunction with phytase use, represents a critical step in optimizing nutrient efficiency and improving sustainability in modern poultry production.Item Feeding for fertility : how early-life nutrition impacts dairy herds(Plaas Publishing, 2025-03) Schultz, Cilé-MariThe Guinness World Record holder cow for lifetime milk production, Smurf from Ontario in Canada, achieved an average daily milk output of 35,4ℓ. Meanwhile, Marília FIV Teatro de Naylo, a cow from Brazil, holds the record for the largest milk yield in 24 hours, producing an astonishing 123,61ℓ through mechanical milking.