Research Articles (Animal and Wildlife Sciences)

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This collection contains some of the full text peer-reviewed/ refereed articles published by researchers from the Department of Animal and Wildlife Sciences

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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.
Feeding for fertility : how early-life nutrition impacts dairy herds
(Plaas Publishing, 2025-03) Schultz, Cilé-Mari
The 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.
Influence of tannin-rich extract from commercial Acacia mearnsii and gallocatechin on ovine cryopreserved semen viability
(Taylor and Francis, 2025) Liman, Mohammed S.; Hassen, Abubeker; Smuts, Mario P.; Biraima, Ahmed D.A.; Sutovsky, Peter; McGaw, Lyndy Joy; Holm, Dietmar Erik; dietmar.holm@up.ac.za
The objective of this study was to evaluate the effect of a tannin-rich extract from commercial Acacia mearnsii (MTE_0), and gallocatechin, a flavonoid compound derived from Acacia mearnsii, on the long-term viability and motility of cryopreserved ovine semen. Six fresh ejaculates obtained from six adult merino rams twice per week for three weeks were allocated to five aliquots (0, 12.5, 25, 50, and 100 µM gallocatechin added into the Optidyl™ extender) before cooling and cryopreservation. Effects of MTE_0 and gallocatechin on post-thawed motility characteristics were analyzed using computer-assisted semen analysis (CASA), and viability (LIVE/DEAD® kit, Molecular Invitrogen, Waltham, MA), oxidative stress (2,7-dichlorodihydrofluorescein diacetate (H2DCFDA, Thermo Fisher®, Waltham, MA)) for reactive oxygen species (ROS), mitochondrial membrane potential (JC-1 MitoTracker, Molecular Invitrogen, Waltham, MA), acrosomal integrity (lectin PNA), and capacitation using merocyanine 540 (M540) and YO-PRO-1 dyes in flow cytometry. Data were analyzed using one-way ANOVA (IBM SPSS 21.0 for Windows, Armonk, NY). Gallocatechin at 25 µM positively affected (p ≤ .001) kinematic parameters including average path velocity (VAP), progressive velocity (VSL), and beat cross frequency (BCF) of cryopreserved semen. Similarly, gallocatechin at 25 µM- improved sperm motility (live 21.99 ± 2.06%), reduced ROS levels (26.45 ± 1.10%), and mitigated premature capacitation (viable and stable 20.08 ± 1.48%) compared to other treatments. Gallocatechin addition to semen resulted in a significant (p ≤ .001) positive effect compared with the MTE_0 extract. It is concluded that gallocatechin inclusion at 25 µM significantly reduces semen deterioration following cryopreservation. This study is the first to introduce gallocatechin as an efficient antioxidant additive to ovine semen to improve its quality during storage. Our findings will help improve post-thaw ovine semen quality and longevity. Future studies to elucidate the mechanism of anti-oxidative stress action of gallocatechin and its derivatives on semen motility and longevity are recommended.
Thermal properties of rhinoceros ovum pick-up probes : possible effects of temperature shock on oocyte maturation potential
(Medpharm Publications, 2024-11) Vorster, L.; De Bruin, Phillippus Rudolf; Smuts, M.P. (Mario); De la Rey, M.; Herbst, C.; Durrant, B.S.; Holm, Dietmar Erik
BACKGROUND: The implementation of assisted reproductive techniques and use of in vitro embryo production has highlighted their potential in attempts to prevent the extinction of the northern white rhinoceros (Ceratotherium simum cottoni). However, in vitro embryo production has proved challenging. Transrectal ovum pick-up (OPU), while done successfully with custom-made aspiration probes (AP), may expose oocytes to detrimental temperature shock OBJECTIVE: This study compares the temperature regulation properties between two AP, made from different materials and used during OPU in southern white rhinoceros (C. s. simum METHODS: The initial PVC plastic AP, produced using a computer numerical control machine, was compared to a modified aluminium AP. A rhinoceros model was constructed using a 210 L water container fitted with heating elements and a water pump. Water was warmed to 37.5-38.5 °C to simulate rhinoceros body temperature. The AP was equilibrated to room temperature (22 simulating summer) or in a walk-in fridge (4 simulating winter) overnight. Temperature loggers were placed inside and on the outside of the AP RESULTS: The aluminium AP equilibrated to the model water temperature within 15 minutes of submersion in the model, while the temperature of the PVC AP remained significantly lower during the three-hour period. The inside of the PVC AP remained significantly colder compared to outside during both winter and summer (33.23 ± 4.28°C vs. 36.51 ± 2.13 °C and 36.04 ± 1.69 °C vs. 37.22 ± 0.92 °C, respectively). There was no significant difference between the inside temperature of the aluminium AP compared to the outside temperature during both the winter and summer simulations (36.75 ± 0.49 °C vs. 37.83 ± 0.40 °C and 37.86 ± 0.16 °C vs. 38.04 ± 0.11 °C, respectively CONCLUSION: This research highlights the importance of using material with good thermal properties during assisted reproductive procedures. It also contributes to further advancement during the establishment of a successful in vitro embryo production protocol for rhinoceros in South Africa
Selection signatures associated with adaptation in South African Drakensberger, Nguni, and Tuli beef breeds
(Springer, 2025) Maxman, Gomo; Van Marle-Koster, Este; Lashmar, Simon Frederick; Visser, Carina; u22608053@tuks.co.za
In the present study 1,709 cattle, including 1,118 Drakensberger (DRB), 377 Nguni (NGI), and 214 Tuli (TUL), were genotyped using the GeneSeek® Genomic Profiler™ 150 K bovine SNP panel. A genomic data set of 122,632 quality-filtered single nucleotide polymorphisms (SNPs) were used to identify selection signatures within breeds based on conserved runs of homozygosity (ROH) and heterozygosity (ROHet) estimated with the detectRUNS R package. The mean number of ROH per animal varied across breeds ranging from 36.09 ± 12.82 (NGI) to 51.82 ± 21.01 (DRB), and the mean ROH length per breed ranged between 2.31 Mb (NGI) and 3.90 Mb (DRB). The smallest length categories i.e., ROH < 4 Mb were most frequent, indicating historic inbreeding effects for all breeds. The ROH based inbreeding coefficients (FROH) ranged between 0.033 ± 0.024 (NGI) and 0.081 ± 0.046 (DRB). Genes mapped to candidate regions were associated with immunity (ADAMTS12, LY96, WDPCP) and adaptation (FKBP4, CBFA2T3, TUBB3) in cattle and genes previously only reported for immunity in mice and human (EXOC3L1, MYO1G). The present study contributes to the understanding of the genetic mechanisms of adaptation, providing information for potential molecular application in genetic evaluation and selection programs.
Determination of calcium and phosphorus digestibility of individual feed ingredients as affected by limestone, in the presence and absence of phytase in broilers
(MDPI, 2024-12-02) Venter, Kyle M.; Angel, Roselina; Fourie, Jamie; Plumstead, P.W. (Peter); Li, Wenting; Enting, Henk; Dersjant-Li, Yueming; Jansen van Rensburg, Christine; christinejvr@up.ac.za
To begin formulating broiler diets on a digestible calcium (Ca) basis, robust Ca digestibility values for ingredients and factors affecting this digestibility are needed. This study had three main objectives: (1) determine the standardized ileal digestibility (SID) of Ca and phosphorus (P) for seven plant-based feed ingredients in broilers, (2) assess the impact of phytate source on SID Ca from limestone (LS), and (3) evaluate the effect of phytase on SID Ca and P for the different ingredients. Two experiments were conducted to satisfy these objectives. In Experiment 1, a 4 × 2 × 2 factorial design was used, with four plant-based feed ingredients (corn, wheat, sorghum, and full-fat soybean meal (FFS)), two LS inclusions in the diet (absence of LS and the inclusion of LS required to achieve 0.65% Ca in the final diet), and two phytase doses (0 and 1000 FTU/kg diet). Experiment 2 utilized a 3 × 2 × 2 factorial design with three plant-based ingredients (soybean meal (SBM), rapeseed meal (RSM), and sunflower meal (SFM)), two LS inclusions in the diet (absence of LS and the inclusion of LS required to achieve 0.65% Ca in the final diet), and two phytase doses (0 and 1000 FTU/kg diet). The trial had eight replicate pens (6 broilers/replicate) per treatment. Data were analyzed using a factorial analysis in JMP Pro 16.0 with means separation performed when p < 0.05, using Tukey HSD. The SID Ca in the absence of phytase for wheat (72.9%) and FFS (69.9%) was higher (p < 0.05) than for sorghum (54.5%) and corn (46.3%). In Experiment 2, the SID Ca in the absence of phytase from SFM (61.0%) was higher (p < 0.01) than RSM (42.7%) and SBM (46.8%). The SID Ca from added LS was affected by the ingredient, with diets containing wheat and FFS resulting in the lowest (p < 0.05) SID Ca versus those containing corn and sorghum irrespective of phytase dose in Experiment 1, and the lowest (p < 0.05) for SBM and RSM vs. SFM in the absence of phytase in Experiment 2. Phytase supplementation increased (p < 0.01) SID Ca and SID P across all feed ingredients compared to non-supplemented diets. There was a two-way interaction (p < 0.01) of LS addition and ingredient on SID P in both experiments. The results of this study provide SID Ca and SID P values from the selected ingredients and show that phytate from different ingredients reacts differently with Ca from LS and should be considered when developing SID coefficients of Ca and P for use in commercial broiler feed formulation. The SID coefficients of Ca and P for the individual feed ingredients evaluated in this study will allow for the further development and transition towards dCa and dP in commercial feed formulation.
Low-cost uncrewed aerial vehicles (UAVs) as a novel tool for welfare assessments on open pen commercial crocodile farms
(Medpharm Publications, 2024-03) Myburgh, Albert; Viljoen, Devon M.; Myburgh, Jan G.; Downs, C.T.; Webb, E.C. (Edward Cottington); Woodborne, S.; albert.myburgh@up.ac.za
BACKGROUND : The welfare of crocodiles on commercial farms in southern Africa requires precise assessment, focusing on stocking densities and pen conditions. However, disputes between animal welfare groups and farm owners persist due to inadequate methodologies for quantifying these factors. OBJECTIVES : This study aimed to address these disputes and enhance crocodile welfare assessment by introducing a novel technique using a low-cost consumer uncrewed aerial vehicle (UAV) and open-source photogrammetry software. The objective was to quantify key welfare parameters accurately and efficiently. METHOD : The study involved applying the UAV-based technique to two large Nile crocodile (Crocodylus niloticus) farms in South Africa. The approach enabled the mapping and surveying of crocodile pens, facilitating the determination of stocking densities, biomass indicators, and other pen-related attributes. Comparisons were made between UAV-derived crocodile counts and farmer estimates. RESULTS : The UAV-based crocodile counts significantly differed from the estimates provided by farmers, underscoring the need for a more precise assessment method. The technique’s cost-effectiveness was evident, with implementation expenses totalling less than R10 000, a fraction of the cost associated with commercial UAV surveys. CONCLUSIONS : The introduced UAV-based technique offers a valuable solution to the ongoing debates regarding crocodile welfare on commercial farms. By quantifying key parameters accurately and economically, it empowers farmers and animal welfare groups to make informed decisions. The method’s ease of adoption, demonstrated through its use by some Southern African crocodile farmers, signifies its potential for widespread application, ultimately contributing to improved crocodile welfare.
The effect of a warmed enema during ovum pick-up on subsequent in vitro oocyte maturation in southern white rhinoceros (Ceratotherium simum simum)
(Medpharm Publications, 2024-08) Vorster, L.; De Bruin, Phillippus Rudolf; Smuts, M.P. (Mario); Durrant, B.S.; De la Rey, M.; Herbst, C.; Holm, Dietmar Erik
BACKGROUND : Rhinoceros are currently one of the most threatened mammal species globally. Slow population growth, increased poaching and habitat destruction have led to increased conservation efforts for each species. Assisted reproductive technologies (ART) have been implemented in an attempt to aid reproductive outputs for the conservation of these endangered species. Developing species-specific ART programmes for wildlife have been challenging. Temperature control during oocyte recovery is essential for ensuring in vitro success. OBJECTIVE : This study is the first to investigate the effect of enema warming prior to trans-rectal ovum pick-up (OPU) on in vitro oocyte maturation in Southern white rhinoceros (Ceratotherium simum simum). METHODS : OPUs were performed on 20 rhinoceros cows from three different game farms in South Africa; oocytes were transported to one of two in vitro fertilisation laboratories for culture. The enema fluid was either warmed to 32 °C or not warmed prior to the OPU. Location of the farm, the different laboratories, ambient temperature, season, aspiration probe temperature, media type and enema temperature were investigated as predictor variables for oocyte maturation success. RESULTS : After considering all other potential covariates, warming of the enema fluid was the only independent predictor of in vitro oocyte maturation success during this study. CONCLUSION : Oocytes retrieved from rhinoceros cows that received an enema warmed to 32 °C were 2.3 times more likely to mature in vitro compared to oocytes from cows that received an unwarmed enema; the findings can be implemented in other rhinoceros ART programmes and in conservation efforts of other endangered mammalian species.
The potential effect of Garlium GEM HCTM as a tick control agent in cattle
(Medpharm Publications, 2024-03) Hagg, Francois Marius; Erasmus, Lourens Jacobus; Stoltsz, Wilhelm Heinrich
As resistance to chemical acaricides increases amongst tick populations, investigations of natural remedies that have acaricidal or tick-repellent effects have become essential in the search for alternatives for sustainable tick control. Garlium GEM HC (Garlium), a natural concentrated garlic product, was supplemented in-feed to beef cattle to determine if it could assist in reducing the number of attached ticks on cattle. Two grams of Garlium was supplemented daily to eight Bonsmara steers over 43 days. A second group of eight steers served as controls. All animals were infested with a similar number of Rhipicephalus appendiculatus adults and Rhipicephalus microplus larvae. Subsequently, the number of attached engorged ticks and the hatchability of the tick eggs were determined. Blood samples were collected from the steers for whole blood analyses. The results were analysed using a twosample t-test procedure. Due to large standard deviations observed, most of the tick parameters were only numerically improved. Although not significant, the number of larvae produced by female R. appendiculatus ticks per host was reduced by 23%. Estimated number of R. microplus larvae produced from ticks harvested from Garlium supplemented cattle were reduced by 42.3% (p = 0.10). No adverse effect was observed on haematocrits or haemoglobin concentrations. Garlium reduced segmented neutrophil count in the treatment group, suggesting that the immune system was less challenged. Although not statistically significant, the effect of reducing the number of larvae produced per host for the two tick species by approximately 20% and 40% respectively, may be of economic benefit to commercial cattle farmers.
Copper (Cu) metabolism in domestic herbivores as guide to criteria for predicting the Cu nutritional status of wild ruminants in southern Africa
(Medpharm Publications, 2024-03) Van Ryssen, J.B.J.; Bath, Gareth
In southern Africa game farming has become an effective way of using underutilised resources and a valuable method of preserving and increasing wildlife numbers. However, little is known about the mineral requirements of wild animal species or the assessment of the mineral nutritional status of these species. To establish criteria for estimating the copper (Cu) nutritional status of wildlife, current knowledge about Cu metabolism and criteria for domestic animals has been used. Since the Cu metabolism of ruminants differs substantially from that of non-ruminants, Cu metabolism in domestic species such as cattle and sheep representing wild ruminants, and pigs and horses as non-ruminant species, has been scrutinised to propose criteria for wild bovids in southern Africa. In the adequate range of dietary Cu intakes, literature suggests that hepatic Cu concentrations in ruminants increase linearly with an increase in Cu intake, allowing a relatively reliable measure of sufficiency. In non-ruminants, hepatic Cu concentrations follow a lag phase during which hepatic Cu concentrations remain relatively constant with increasing dietary Cu intakes of more that 25 times their requirements. A consequence is that non-ruminants can tolerate much higher dietary levels of Cu compared to ruminants. It is proposed that at liver Cu concentrations of < 20 mg/kg dry matter (DM), a wild ruminant could benefit from Cu supplementation; liver Cu concentrations of between 20 and 300 mg Cu/kg DM suggest an adequate Cu intake; concentrations of 300 to 500 mg/kg DM indicate a potentially unhealthy accumulation of Cu, while liver Cu concentrations of > 500 mg/kg DM indicate that the animal probably consumed more Cu than required and might be at risk of developing Cu toxicosis.
Effect of rainfall interception and resting period on the soil seed bank
(Frontiers Media, 2024-07) Magandana, Thabo Patrick; Hassen, Abubeker; Tesfamariam, Eyob Habte
The ecosystems across the world are affected by diverse impacts of climate change. Climate change will also affect soil seed bank as the seed bank is determined by the plants that are above the ground. This study was conducted to determine whether rainfall interception and resting period will affect the soil seed bank or not. Rainfall interception was employed as main plot treatment at four different levels—namely, 15%, 30%, 60%, and 0%—and the main plot treatments were each replicated five times using the rainout shelters arranged as main plot treatments in a split-plot experimental design. The main plots are 49 m2 (7 m × 7 m) in size and were covered by metal frame structures with Vshaped clear acrylic bands on top without ultraviolet filter, and these plots were sub-divided into two sub-plots to determine the effect of resting periods (70 and 90 days). The soil samples were 8 cm in diameter and 20 cm in depth (1,005 cm3 ). We used seed emergence method rather than seed separation method to determine the soil seed bank due to the very small size of some seeds for some species. The 60% rainfall interception resulted in significantly high forb densities at both resting periods. The forb densities decreased by 32 and 35% at 15% and 30%, while they increased by 195% at 60% rainfall interception compared to 0% rainfall interception at 70-day resting period. Resting period significantly affected grass densities at 60% rainfall as the densities were higher at 70- than 90-day resting period. At 90-day resting period, grass densities were significantly higher at 0% rainfall interception than the rest of the treatments, while the grass densities were significantly lower at 60% rainfall interception. The 60% rainfall interception resulted in significantly (p< 0.05) higher total densities (forbs and grass) in both resting periods. Total density increased by 2.9% and 143.48% at 15% and 60% rainfall interception, respectively. Our results show that drought has a negative effect on grass soil seed bank, while it improves the forbs soil seed bank. Furthermore, the resting period has no significant effects on soil seed bank in grasslands.
Effects of dietary supplementation with Acaciamearnsii tannin extract on carcass characteristics and meat quality of lambs
(BMC, 2024-08) Venter, Megan; Hassen, Abubeker; Pophiwa, Pamela; Webb, E.C. (Edward Cottington); abubeker.hasssen@up.ac.za
BACKGROUND: Plant extracts are used as possible methane mitigants and to replace antibiotic feed supplements previously used prophylactically to improve the adaptation of lambs in intensive feeding systems. This study investigated the effects of Acacia mearnsii tannin extract used as anti-methanogenic feed additives on carcass and meat quality of lambs. METHODS: Forty Dohne Merino lambs, with an initial mass between 23.90 kg and 37.40 kg, were first stratified according to their initial body weight and thereafter one of the eight lambs with similar body weight were randomly assigned to four treatment groups (n=10 lambs/treatment). The lambs were fed ad libitum with a basal total mixed ration. Four experimental diets were formulated: TMR diet (control); TMR diet with Rumensin® at a dosage of 75 mg/ kg of DM feed (Monensin; Positive control); TMR diet with raw condensed Acacia tannin at 20 g/kg of DM feed (Crude tannin); TMR with addition of encapsulated condensed Acacia tannin at 20 g/kg of DM feed (Encapsulated condensed tannins). The lambs were slaughtered at a live mass of about 50 kg after a 19 week trial period. RESULTS: Dietary tannin additives did not affect the carcass composition or colour aspects of lamb meat. However, there were minor changes in fatty acid profiles, particularly in the intramuscular adipose tissue. The addition of encapsulated tannin extract resulted in a higher proportion of C18:2n6t (0.15%±0.03 vs. 0.19%±0.03; p<0.05), C18.3n3 (0.24%±0.04 vs. 0.29%±0.04; p<0.05), C22:6n3 (0.02±0.01 vs. 0.05±0.03; p<0.05), in comparison to monensin. This improvement in fatty acid profiles is presumably beneficial for human health, but it could affect the sensory quality of meat. CONCLUSION: Our results suggest that Acacia mearnsii tannin extracts can be included as anti-methanogenic feed additives in lamb diets without compromising product quality.
The impact of myostatin variants on growth traits in South African Bonsmara beef cattle
(Springer, 2024-11) Madula, Rendani Asnath; Visser, Carina; Van Marle-Koster, Este; carina.visser@up.ac.za
Double muscling occurs when the myostatin (MSTN) gene is deactivated due to a series of mutations, leading to uncontrolled muscle growth and excessive muscle fiber accumulation, as the gene can no longer effectively regulate muscle development. This study aimed to assess the impact of MSTN variants and their combinations on growth traits, namely direct birth weight (BWDIR), direct weaning weight (WWDIR), average daily gain (ADG) and feed conversion ratio (FCR) in the South African (SA) Bonsmara. Genomically enhanced estimated breeding value (GEBVs) for traits of interest, and MTSN genotypes for SA Bonsmara animals were available for the study. Thirteen MSTN variants (Nt821, Q204X, F94L, E226X, E291X, C313Y, Nt419, S105C, D182N, Nt414, Nt324, Nt267, and Nt748) were routinely genotyped using the IDBv3 SNP array. Genotypic frequencies of MSTN variants ranged from 1.18% for Q204X to 35.02% for Nt748. No association was observed between the Nt267 variant and any growth traits, while both Nt748 and Nt414 variants affected WWDIR, ADG and FCR (p < 0.05). The results of the effect of multiple variants on growth traits indicated that there was an additive effect when more than one MSTN variant was present in an individual. This study is the first study to report the impact of MSTN variants on traits of economic importance in the SA Bonsmara breed.
Risk factors underlining reproductive performance in smallholder beef cattle herds of South Africa
(Springer, 2024-11) Nkadimeng, Marble; Van Marle-Koster, Este; Nengovhela, Nkhanedzeni B.; Ramukhithi, Fhulufhelo V.; Mphaphathi, Masindi L.; Rust, Johannes M.; Makgahlela, Mahlako L.
Improving the historically low reproductive performance of beef cattle in smallholder systems is essential for its productivity and profitability. Therefore, identifying and addressing risk factors associated with low performance in this system present an opportunity for improvement. The study aimed to evaluate the effect of animal and management risk factors on pregnancy rate (PR), fetal and calf loss (FC), calving interval (CI) and days open (DO) in smallholder beef cattle farms. A multi-stage selection approach was conducted in five provinces of South Africa. Cow records (3694) collected from 40 smallholder herds over two years (2018–2019) were analysed. Data on animal and herd management factors including body condition score (BCS), cow age class, breed type, lactation status, culling old/non-productive cows, record-keeping, and breeding and calving seasons were recorded. The GLIMMIX procedure was computed to determine risk factors associated with performance indicators (PR, FC, CI and DO). Risk factors highly associated with performance were breed type, BCS, cow-age class and breeding/calving season (P ≤ 0.05). Indicators FC, DO and CI increased with decreased BCS, autumn calving seasons, and in first calvers and aged cows. Whereas, PR increased with increasing odds of BCS and breeding seasons between December-March, November-February and January-March. Optimizing reproductive performance in smallholder beef cattle herds may involve managing cow body condition, breeding with adapted genotypes and synchronizing breeding with favourable seasons. Therefore, record keeping and regular monitoring of herd nutrition, climate and breed performance may be significant in improving reproductive performance in smallholder herds.
Evaluation of body calcium and phosphorus composition of the Cobb 700 genotype during growth
(Taylor and Francis, 2025-02) Salisbury, Frances; Gous, R.M.; Cowieson, A.J.; Jansen van Rensburg, Christine; Rochell, Samuel J.; Walters, H.
1. The amount of calcium and phosphorus in the empty, feather-free bodies of Cobb 700 breed males and females was measured from hatch to 15 weeks of age.2. A four-phase ad libitum feeding programme was used to feed 400 chicks of each sex. Feeds contained commercial levels of calcium and phosphorus which met or exceeded the requirements for energy, protein and amino acids. All birds were weighed weekly. Ten birds per sex were sampled at 0, 7, 14, 28, 42, 56, 70, 84 and 105 d of age. Defeathered birds were minced, freeze-dried and then analysed for protein, ash, calcium and phosphorus content.3. Amounts of Ca in males and females at 105 d averaged 54 and 37 g, respectively, and 105 d P content in males and females averaged 35 and 27 g, respectively. The allometry of ash, Ca and P with empty, feather-free body protein was assessed. Ash was isometric with body protein, while an allometric exponent greater than 1 was established for Ca and P with body protein.4. The allometric models and means for Ca and P relative to body protein were compared with models and means found in the literature. Comparison of the Ca/protein ratios with previous data suggested that modern broilers may not reach their potential bone mineral deposition with current dietary guidelines, even when growth rates were maximised.5. Theoretical allometric relationships between Ca and P in bone and bone-free body and body protein have now been proposed. The allometric relationship between Ca and P and empty, feather-free body protein offers a suitable way to model the growth of these minerals in the broiler body.
The use of management and hormonal oestrous synchronisation on indigenous sheep reared extensively
(Science Publications, 2024) Maqhashu, Ayanda; Ngcobo, Jabulani Nkululeko; O'Neill, Hester Adriana; Sebei, Phokgedi Julius; Ramukhithi, Fhulufhelo Vincent; Mapholi, Olivia; Shingange, Rimbilana N'wa-Nghondzweni; Nephawe, Khathutshelo; Nedambale, Tshimangadzo Lucky
As the global population increases, demand for animal products will result in increased livestock-related greenhouse gas emissions that contribute to climate change. One of the strategies for reducing this impact would be the improvement of indigenous livestock reproductive efficiency that are hardy and well adapted to harsh environmental regions. The use of reproductive technologies increases efficiency of animals necessary for profitable production. This study evaluated the effects of age and body condition score on the response and duration of oestrus in synchronized Bapedi ewes, conserved ex-situ in vivo and in situ. Study ethics procedures were approved by the Agricultural Research Council Irene animal ethics committee. Ninety-one Bapedi ewes (<2 and 3-6 years of age) were used in the study from five different research stations (Towoomba = 12, Tompi Seleka = 19, Mara research station = 20 and Agricultural research council Irene = 40). Ewes were chosen based on the Body Condition Scores (BCS) <3 and BCS≥3 on a scale of 1-5 during breeding season (March-June). For estrous synchronization, Controlled Intravaginal Drug Release (CIDR®) dispensers were inserted for 9 days and 300 IU of equine chorionic gonadotrophin was injected intramuscularly after CIDR removal. Oestrus detection was done for a period of 72 h, from CIDRs withdrawal with a vasectomized ram and ewes that were receptive to the ram were hand mated with Bapedi rams. Data was subjected to GLIMMIX procedure and Chi-square in SAS 2009. The results were measured significant when p<0.05. There were no significant differences observed in the oestrus response of ewes regardless of age (p>0.05) and method of conservation. The oestrus response was higher for ewes with BCS≥3 compared to the lower BCS group (p<0.05). Old and lower BCS ewes showed oestrus signs earlier (23±2.8; 21±4.1); (22±4.1; 20±5.3) and with a shorter duration (23±8.2; 20±6.2); (22±4.0; 23±3.2) compared to young and higher BCS groups (onset of oestrus: 34±2.0; 32±2.4); (36±1.3; 35±2.3) duration (30±1.3; 29±1.5); (33±5.0; 32±6.0) (p<0.05). Higher oestrus was observed on ewes with BCS ≥3. Young and high BCS ewes had a delayed onset of oestrus that lasted longer compared to old and lower BCS ewes. The conception rate was 65, 67, 53 and 70% for ARC, Towoomba, Tompi Seleka and Mara Research Station respectively (p>0.05). Towoomba farm had a significantly lower litter size recorded compared to all the other farms. The prolificacy of Bapedi sheep was 1.30±0.6 1.28±1.3; 1.29±0.8 and 1.31±0.5 for ARC, Towoomba, Tompi Seleka and Mara farms respectively. It was concluded that the conservation method did not affect the reproductive performance of Bapedi sheep. Bapedi ewes can be synchronized successfully with an acceptable conception rate without supplementary feeding. It is recommended that flush feeding should be done to improve the litter size.
Editorial : new challenges and future perspectives in nutrition and sustainable diets in Africa
(Frontiers Media, 2024-03) Schonfeldt, H.C. (Hettie Carina); Gong, Yun Yun; Essilfie, Gloria L.; hettie.schonfeldt@up.ac.za
No abstract available.
The potential of Moringa oleifera as a sustainable broiler feed additive : investigating Awareness, perceptions and use by broiler farmers and moringa farmers in South Africa
(MDPI, 2024-03) Lungu, Nobuhle Sharon; Maina, Joyce G.; Dallimer, Martin; Van Marle-Koster, Este; este.vanmarle-koster@up.ac.za
Moringa oleifera’s high nutritional value and bioactive properties have attracted significant scientific research interest as an additive in broiler feed for sustainable broiler production. The tree’s multifunctional characteristics make it a potent alternative growth promoter for broilers and a valuable resource to address Sustainable Development Goals related to poverty alleviation, food security, good health, and responsible consumption. Moreover, it provides a less expensive and environmentally friendly alternative for broiler farmers. However, less is known about the awareness, perceptions, and prevailing practices of broiler farmers and M. oleifera farmers regarding the plant’s use as an additive. This study determined the awareness, perceptions, and practices of M. oleifera use among broiler and M. oleifera farmers in South Africa. Quantitative data collected from 165 purposively sampled small-scale broiler farmers, along with qualitative insights from 11 key informants, indicated that 66.7% of respondents, primarily females, knew about M. oleifera but lacked awareness of its benefits for broilers (82.4%). Awareness varied significantly (p < 0.05) by gender. Only 10.9% of those aware used M. oleifera, predominantly small-scale female farmers. Leaves and stems were common parts used, added to feed, or infused in water. Perceived benefits included improved growth rates and reduced mortalities. Large-scale broiler farmers expressed interest if provided with more information on the nutritional benefits and the availability of bulk M. oleifera to sustain their large operations. The study underscores the need for targeted awareness campaigns, especially among female farmers, and providing guidelines for M. oleifera use. Formulating broiler diets that include M. oleifera as an ingredient will require a consistent supply, which is currently lacking. Therefore, there is a need to address the production capacity to meet the requirements of larger broiler operations.
Is soya sufficient in the NSNP?
(Plaas Publishing, 2023-06) Muller, Carmen; Pretorius, Beulah; Schonfeldt, H.C. (Hettie Carina); hettie.schönfeldt@up.ac.za
The South African National School Nutrition Programme (NSNP) was introduced in 1994 by the government as part of the Reconstruction and Development Programme to feed primary school children.
Consumer awareness, utilization, and acceptance of orange-fleshed sweet potato (Ipomoea Batatas (L.) Lam) value-added food products in Elgeyo Marakwet County, Kenya
(Enviro Research Publishers, 2024-04) Cheboi, Juliana jepkemoi; Abong, George; Greathead, Henry Michael Rivers; Keyster, Marshall; Nkukwana, Thobela T.
Sweet potatoe is a crucial crop for food security. promoted in Kenya due to its reported health benefits and resilience to drought. The benefits and application of the sweet potato with orange flesh (OFSP) in Elgeyo Marakwet County have, however, not been established. The current research sought to establish knowledge, method of utilization, and acceptability of specialty products made from OFSP. Information on sweet potato knowledge and use was gathered from 201 smallholder farmers in Endo Ward, Elgeyo Marakwet County, using a multi-stage sampling technique. Promotion of recipes of OFSP value-added products was undertaken among 30 selected farmers through practical demonstration and a farmer participation approach. The evaluation was undertaken through semi-structured questionnaires and scoring sheets for the preferred products and reasons to support their preferences. The results indicated that 82.6% of farmers in Elgeyo Marakwet are aware Compared to other crops, sweet potatoes are easier to grow and more suited to difficult climates (80.1 %). They were also aware of the advantages OFSP has for health (61.7%) and as a household food security crop (79.1%). However, 89.1% of the farmers have inadequate knowledge and skills in value addition. The majority of the farmers (70%) boil the sweet potatoes while 30% make snacks out of the OFSP. Consumer knowledge, utilization, and acceptability are influenced by demographic factors such as gender, education levels, size of land, and occupation. Products made with OFSP puree are the most preferred over wheat justifying its uses to produce acceptable and nutritious chapati, mandazi, and yogurt as part of diversification from the current practice of simply eating the boiled roots. These results suggest that increased efforts are required to educate farmers about the nutritional advantages of cultivating and consuming OFSP. to boost agricultural value addition and boost the amount of vitamin A in households’ diet.

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