Theses and Dissertations

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Epididymal bull spermatozoa morphometrics post cryopreservation in Moringa oleifera leaf extracts supplemented tris-egg yolk semen extender
(2026-05-19) Negota, Nkhumeleni Cathbert; Bhebhe, E.; Mphaphathi, M. L.; Nedambale, T. L.
Bull semen preservation techniques, especially cryopreservation of epididymal sperm, are vital for genetic preservation and can enhance in vitro fertilization (IVF) efforts. Spermatozoa are prone to oxidative damage during assisted reproductive technologies, impacting fertility. However, adding Moringa oleifera leaf extract (MOLE) to a tris-egg yolk (TEY) extender improves sperm motility, viability, and post-thaw fertility. The objective is to establish a protocol for preserving semen from slaughtered bulls, allowing for sperm retrieval from genetically superior animals post-death, thus offering economic benefits and supporting a sustainable socioeconomic framework. The broad objective was to develop a suitable protocol for semen preservation from the epididymis of slaughtered bulls to enable the recovery of spermatozoa from genetically superior bulls after death. Testicles and ovaries were collected from a Makhado slaughterhouse and transported to the laboratory at a temperature of 5 °C. The flushing technique was employed to retrieve semen from the epididymis. The semen samples were then extended using a TEY solution supplemented with varying levels of MOLE. In the first experiment, the motility, viability, and morphology of spermatozoa were assessed in bull semen samples stored at 5 °C over different time intervals. The second experiment involved keeping bull testicles at 5 °C for varying durations (0, 2, and 4 h) before the recovery of semen from the epididymis. During the third experiment, the semen was diluted with a TEY extender containing different amounts of MOLE and was subsequently frozen using the LN2 vapour method. In the fourth experiment, the fertilization ability of cryopreserved semen (obtained at different heights of the LN2 vapour method) was evaluated through IVF utilizing various concentrations of MOLE. Data analysis was conducted using the General Linear Model (GLM) procedure in Minitab version 2019 to assess treatment effects with a 95% confidence interval. A Computer-Aided Sperm Analyzer (CASA) was employed to evaluate spermatozoa characteristics, while live and dead spermatozoa were manually assessed following staining procedures. The IVF workstation was utilized for the fertilization process. Different semen extenders significantly affected sperm motility (P<0.01). The TEY+0% MOLE extender had the highest total motility, similar to TEY+4% and TEY+8% MOLE but higher than TEY+12%. Live spermatozoa values were consistent at 0 and 24 h, but lower after longer storage. Total motility decreased with longer storage before recovery from the epididymis (0-4h). During cryopreservation, TEY+8% MOLE had the highest viability, followed by TEY+4% MOLE. xvii Sperm viability was higher at 5 cm compared to 7 cm above LN2. The highest fertilization rate was in TEY+12% MOLE, similar to TEY+0% and TEY+8% MOLE. LN2 levels did not affect total fertilization or zygote stages at 0 PN and >2 PN, but interactions did affect presumptive zygotes at stage 1 PN. In conclusion, adding MOLE to the TEY extender improves sperm motility and viability of epididymal post-slaughter bull sperm for up to 120 h at 5 °C. The TEY+MOLE extenders significantly enhanced motility parameters, with TEY+8% MOLE showing the best sperm characteristics. While prolonged storage decreases sperm quality, acceptable results were noted within 48 h before freezing. Slow cooling of semen straws at 5 cm above LN2 yielded better sperm survival than cooling at 7 cm. Different MOLE concentrations improved fertilization ability during IVF, with TEY+12% MOLE achieving the highest fertilization rate. However, significant effects on total fertilization and zygote development were not observed, though interactions between MOLE concentration and LN2 levels did impact zygotes at stage 1 PN.
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Nitrogen metabolism in meatmaster sheep fed brewers grain as a supplementary source of protein
(2026-05-19) Molokomme, Maite; Baloyi, J. J.; Mahlako, K. T.
This study aimed to examine how nitrogen metabolism in sheep is affected when brewers’ grains are added to diet as a supplementary protein source. Eight Meatmaster rams (average live weight 30 ± 3.2 kg; approximately 6 months old) were randomly allocated to four iso-energetic and iso-nitrogenous diets, which contained 0%, 10%, 20%, and 30% BSG, denoted BSG0, BSG10, BSG20, and BSG30, respectively. The experiment was conducted using a 4 × 4 Latin square design in duplicate. The sheep were housed in metabolic cages for 19 days, consisting of 14 days adaptation and 5 days for data collection. During this period, feed intake, faecal and urinary outputs, and excreta were measured. Feed and excreta samples were analysed for chemical composition, including dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), ash, neutral detergent fibre (NDF), acid detergent fibre (ADF), and condensed tannins (CT) as a percentage of dry matter. These data were used to calculate nutrient intake (g/day); apparent digestibility coefficients (%) for DM, OM, CP, EE, NDF, and ADF; nitrogen metabolism parameters (nitrogen intake (NI), faecal nitrogen (FN), urinary nitrogen (UN), total nitrogen excretion (TNE), and nitrogen retention (NR) in g/day, rumen fermentation and microbial parameters (allantoin concentration (mmol/L), microbial nitrogen yield (g/day), microbial true protein (MTP, g/day), digestible organic matter in the rumen (DOMR, g/day), nitrogen utilisation efficiency (Emns, g N/kg DOMR) and the metabolizable energy (ME, MJ/day) intake. The CT content (as a percentage of dry matter) in the BSG10 diet was significantly higher (P<0.05) than in the other dietary treatments. No significant differences (P>0.05) in the intake of DM, OM, DOMI, and ME were observed. However, CP, EE, acid detergent fibre (ADF), and neutral detergent fibre (NDF) intakes varied significantly (P < 0.05) across treatments. The apparent digestibility coefficient (ADC) of EE showed no notable difference (P>0.05) among BSG0, BSG10, and BSG20. There were no significant differences (P>0.05) in the digestibility coefficients of DM, OM, NDF, ADF, and CP across all treatments. The results showed differences in NI, FN, UN, TNE, and NR(P<0.05) among the treatments. Allantoin concentrations, microbial N yield, MTP, DOMR, and Emns across all treatments were not significantly different (P>0.05). The study confirmed that brewers’ grain is an effective protein source for sheep diets, without negatively affecting rumen function or nitrogen metabolism. The crude protein content of 22.6% in the BSG makes it a suitable partial substitute for traditional protein feeds. The presence of CT in the supplemented diets appears to enhance protein retention by slowing ruminal proteolysis and reducing nitrogen loss through urine. Trends in nitrogen use and allantoin excretion indicate increased rumen microbial activity and microbial protein synthesis with the inclusion of BSG. Thus, BSG can be a suitable supplementary protein source.
Open Access
Exploring cattle tick infestations, farmers knowledge, attitudes, and control practices in selected villages of Collins Chabane Local Municipality, Limpopo Province
(2026-05-19) Moseri, Uhone Budi Princess; Bhebbe, Evison; Chitura, Teedzai
Tick infestations remain a significant constraint to cattle health and productivity in communal farming systems of South Africa. A cross-sectional mixed-methods approach was employed, combining tick surveys, clinical examinations of cattle, and a farmer’s knowledge, attitudes and perceptions (KAP) survey conducted during routine dipping days. Adult ticks were systematically collected from cattle, preserved in 70% ethanol and identified morphologically using standard taxonomic keys. A clinical evaluation checklist was used to record tick burden, species composition, attachment sites, tick-induced lesions, and body condition scores. Cattle farmers’ data was collected through face-to-face interviews using a structured questionnaire administered in Xitsonga language. A total of 967 adult ticks were identified, comprising eight species, with Amblyomma hebraeum and Rhipicephalus decoloratus being the most prevalent across both villages. Ntlhaveni village exhibited a higher overall tick burden and greater abundance of Rhipicephalus microplus and Hyalomma rufipes than Matiyani village, suggesting that environmental conditions, grazing patterns, and management practices likely influenced spatial variation. High tick burdens were observed in both villages, with mixed-species infestations being common. Age and physiological status significantly influenced tick burden and tick-induced lesion severity, with growing and pregnant cattle more severely affected. Tick lesions, hair loss and skin thickening were prevalent, and most cattle displayed low to moderate body condition scores, suggesting negative implications for productivity. Despite limited formal livestock training, most farmers demonstrated practical knowledge of tick identification and inspection. However, nearly half of the respondents reported year-round high tick infestations and perceived a decline in acaricide effectiveness, suggesting potential acaricide resistance. Tick infestations were associated with reduced milk production, poor body condition, increased calf mortality, and higher treatment costs. Overall, the study highlights the substantial health and economic burden of ticks in communal cattle systems, underscoring the need for location-specific, integrated, and sustainable tick control strategies supported by strengthened veterinary extension services.
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Effects of Hot Red Pepper (Capsicum annum) on Growth Performance and Visceral Organs of Ross 308 Broiler Chickens
(2026-05-19) Mpyane, Zelda Tebogo; Netshipale, A. J.; Mahlako, K. T.
The study investigated the effects of hot red pepper powder’s provision method and level of inclusion on the growth performance and size of visceral organs and tissues of broilers to contribute to the mitigation of antimicrobial resistance (AMR). Three hundred female Ross 308 day-old chicks were used, housed in a deep litter, naturally ventilated, open-sided. Two pepper provision methods (with diet and water) and five levels of pepper inclusion (0, 0.75, 1, 1.25, and 1.5%) were used in a 2 x 5 factorial arrangement with three replications. Broilers were fed starter-finisher antibiotic-free diets from day 8 to 49. Birds had access to water. Birds were weighed on day 8 and at the end of each growth phase. Feed was weighed when offered, and the leftovers were recorded at the end of each week. Water was measured when offered, and refusal was recorded the next morning. On day 50, a random bird from each pen was selected and slaughtered to collect data on the size of visceral organs and tissues. Analysis of variance was conducted using the General Linear Model procedure of Minitab version 19. Means were separated using Tukey’s and LSD procedures at the p< 0.05 significance level. During the starter period, higher (P< 0.01) ADFI of 64-66 g/b/d was observed for the water method with inclusions of 0.75, 1, and 1.5%; heavier (P< 0.01) birds were on pepper in feed (493 g/b) and at 1.25% inclusion (510 g/b) than for 0.75, 1, and 1.5%; and FCR was lower (P< 0.05) at 1.5% than for the control. During the grower phase, provision method and inclusion level did not affect (P> 0.05) growth performance. During the finisher phase, the interaction of the provision method and inclusion level affected ADWI (P< 0.05) and FCR (P> 0.01). Water intake of 268 mL/b/d was higher (P> 0.05) at 1.25% in water than at 1% in water and 0 and 1.5% with feed; poor (P> 0.01) FCR of 4.8 was observed for 0.75% in water, which was like that of 1.5% in feed, during finisher. No mortality occurred during the experimental period. Adding pepper to water increased (P<0.01) spleen size by 0.08%, and liver size was 0.2% bigger at 1.5% inclusion than at 0 and 0.75%. These findings show that adding pepper up to 1.5% is safe for the birds, but the findings on growth performance were not conclusive.
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Broiler management practices for small-scale farmers and their impact on growth performance
(2026-05-19) Ndlovu, Sithembisile; Netshipale, A. J.; Mahlako, K. T.
The broiler management practices that were likely to be neglected by small-scale farmers and their effects on broiler growth were investigated. For the management practice study, small-scale broiler farmers who reared 4,000 birds or fewer were targeted. The study investigated 100 farmers in the Bushbuckridge Local Municipality. An exploratory study was conducted to identify the broiler management practices employed by small-scale farmers. A structured questionnaire was used. The collected data included household information on type, ethnic group, marital status, and occupation. The farmers' information included the enterprise’s location, age, gender, education level, farming experience, their farming practices, and standard broiler management techniques. Management practices included the number of broiler houses and their carrying capacities, the number of birds housed, the application of an all-in, all-out rearing strategy, rest periods for the broiler house(s), a vaccination programme, management of sick birds, record-keeping, and waste disposal. Foot bath, feed and water wastage, adjustability of feeders and water troughs, number of feeders and water troughs, heating system, ventilation system, and bedding (colour, wetness, and compactness) were observed during farm visits. The sizes of broiler houses and the depth of the litter were measured. Data was coded for analysis purposes. Data on vaccination, footbath, all-in-all-out, drinkers' and feeders' adjustments, stocking rate, bedding height, house resting, and broiler-to-equipment ratios (per drinker and per feeder) were categorised into adherence and non-adherence/neglect to management practices. The Statistical Package for the Social Sciences/SPSS (IBM Corp., 2023), Version 29.0.0.0 (241), was used to analyse the data. There were 47% female-headed and 53% male-headed households. Sixty-nine percent of farmers were single, 24% were married, and 7% were widowed. The prevalence of male (51%) and female (49%) farmers was quite similar. Youth farmers made up 53%. Farmers had 13% primary, 40% secondary, and 47% higher education. Sixty-five percent of farmers had less than 5 years of farming experience, while the remainder had more. Agriculture: 60% of farmers earned their living solely from farming, whereas 40% earned it from both on-farm and off-farm sources. Most (68%) enterprises were in rural areas. In terms of capacity, most farmers had a single broiler house (74%), and houses that could accommodate 100-500 birds were most common (76%). Most farmers adhered to management practices of stocking rate (94%), house resting (81%), vaccination (94%), all-in and all-out strategy (90%), bird drinker and feeder (equipment) ratio (76%), and equipment adjustment (90%). The two management practices that farmers most neglected were bedding height (96.4%) and foot baths (85%). Overall, the most concurrently neglected practices were adequate resting of the broiler house, adequate bedding, and footbath (57%). For the determination of the effects of the neglected standard management practices on growth performance study, thirty (30) small-scale broiler farmers were purposively sampled. The management strategies investigated and the number of enterprises sampled were: 0 = adhering to the five key management practices (7); 1 = inadequate resting of the house and bedding, and no footbath (7); 2 = inadequate resting of the house and bedding, and no footbath (7); 3 = inadequate bedding and no footbath (7), and 4 = inadequate resting of the house and bedding, no footbath and vaccination, and heights of drinkers and feeders not adjustable (i.e., neglect of the five key managerial practices) (n = 2). A single broiler house, stocked with day-old chicks, was targeted per farmer. Observation tools (record sheet and measurements) were used to collect data for broiler numbers, body weight, mortality, and feed offered. Researchers weighed birds on days 8, 22, and 36. Data were subject to Independent-Samples Kruskal-Wallis Tests in SPSS. Differences in distributions across the management practices were compared, and significance values were adjusted by the Bonferroni correction for multiple tests. Weight gain days 8-21 and day 21 weight were higher (P<0.05) for Strategies 0 (52 ± 8.2 g/b/d and 913 ± 120.0 g) and Strategy 3 (50 ± 5.8 g/b/d and 880 ± 88.7 g) than for Strategy 4 (28 ± 4.1 g/b/d and 548 ± 62.2 g). Fewest broilers died under Strategy 0 (8 ± 6.0), some under Strategies 1 (23 ± 15.1) and 3 (11 ± 8.0), and many under Strategy 4 (45 ± 12.0) during days 1-35. Neglecting house rest and vaccination practices led to poor performance under Strategy 4. Key stakeholders should prioritise these two practices for broiler farming to contribute to poverty eradication and income generation for all.
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The effects of stocking density and housing on feed efficiency and growth performance of broiler chickens
(2025-09-05) Netshipale, Fhulufhelo; Bhebhe, E.; Mahlako, K. T.
The poultry industry in South Africa is a significant contributor to the agricultural sector, with broiler production accounting for 80% of total broiler production within the Southern African Development Community. However, the industry faces challenges such as high input costs, particularly feed, and lack of domestically produced ingredients. To maximize broiler performance, producers should improve feed efficiency, which is crucial for profitability and long-term viability. Factors affecting feed efficiency include energy level of feed, temperature in the house, litter quality, feed wastage, and disease presence. Optimal growth performance is crucial, as it directly impacts the time it takes to bring products to market and the overall quality of the final product. This study was to compare broiler performance under small scale production between fan exhaust houses and open-sided, naturally ventilated houses. The research aimed at determining the effects of stocking density and housing type on broiler performance, welfare, and economic implications. High stocking density is a strategy used by broiler farmers to maximize floor space, but it can have adverse effects on chickens, including lower growth rates, feed intake, and feed efficiency. High stocking densities can lead to diseases, increased litter moisture, higher temperatures, and increased competition for feed, affecting broiler growth. Lower stocking densities result in reduced oxidative stress and better growth performance. Broiler houses are essential for optimal feed intake and feed efficiency in poultry farming. Natural ventilation systems, which control airflow and temperature, are common in small-scale productions, while mechanical ventilation systems require efficient fans. The choice of housing system and design significantly impacts the welfare and productivity of broilers. Stocking density and housing type significantly impact animal well-being and performance. The economic implications of stocking density and housing type are complex, requiring a careful equilibrium to maximize production costs, revenue, and total profitability in broiler chicken farming. Ethical considerations, such as clean and disinfected pens and access to clean water and feed, are essential for broiler welfare and health. The experiment involved a study on broiler houses with different designs, including natural ventilation and fan exhaust houses. A total of 300 Arbor Acre birds were housed in these houses, with half in naturally ventilated houses and the remaining in ventilated houses. Data collection began on day 8, and weekly feed intake was determined by subtracting left over feed from the total feed supplied for each seven-day interval. Feed conversion ratio was obtained by dividing the average weekly feed consumption per bird per replicate by the average weekly weight gain per bird per replicate. The results showed that broiler performance was not significantly affected by stocking density however housing type had a significant difference on feed intake in house 1 (H1) but not on feed efficiency. Overall stocking density and housing did not have any significant difference on broiler performance. For economic reasons farmers under small scale farming can use naturally ventilated houses.
Open Access
Effect of location and drying methods on nutrient composition, apparent digestibility, growth performance and carcass characteristics of South African Mutton Merino Lambs fed different levels of dried marula fruit peels
(2024-09-06) Murovhi, Ronewa; Murovhi, R.; Mikasi, M. S.
The purpose of this study was to determine the effect of location and drying methods on nutrient composition of dried marula fruit peels and apparent digestibility, and growth performance as well as carcass characteristics of South African mutton merino lambs fed different levels of dried marula fruit peels. Marula (Sclerocarya birrea) is a medium sized tree belonging to the Brachystegia genus. Several experiments were conducted to evaluate the chemical composition of dried marula fruit peels where the DM, OM, CP, CF, ADF, NDF, and GE were determined. All the data in this experiment were subjected to analysis of variance for a 2x2 factorial in a completely randomised design using a GLM procedure of Minitab 19(Minitab, 2019). Tukey’s studentised multiple range test determined statistically significant differences among the means. The dry matter of fresh marula fruit peels has shown a significant difference (P<0.01). The dry matter of fresh marula fruit peels from Tzaneen using freeze and oven-drying methods was higher than those from Phalaborwa. The dry matter, crude protein, ash, ether extract, acid detergent lignin, and gross energy contents of dried marula fruit peels for both locations and drying methods were not significantly different (P>0.05). The crude fibre, Acid detergent fibre, and nitrogen detergent fibre results for both location and drying methods were significantly different (P<0.01). The crude fibre and nitrogen detergent fibre from Tzaneen were found to be higher than those from Phalaborwa when a freeze-drying method was used. However, when using an oven-drying method, the crude fiber, nitrogen detergent fiber, and acid detergent lignin contents were higher in Phalaborwa. Apparent digestibility of DM, CP, and OM of the diet was determined in a completely randomised design and the means were compared using a Tuckey method at a 95% confidence level. The experiment was conducted in the last ten days of growth trial. A total of 9 male South African mutton merino sheep of approximately 35kg of weight were used in this experiment. The results revealed that the inclusion levels of dried marula fruit peels in the animal diet did not affect (P>0.05) the CP intake. However, a significant difference (P<0.01) was observed in the OM intake by the lambs. The inclusion levels of dried marula fruit peels in the diet did not affect (P>0.05) the faecal excretion of nutrients by lambs. A non-significance difference (P>0.05) was observed in the digestibility of nutrients. The determination of growth performance and carcass characteristics of the lambs fed different levels of dried marula fruit peels was conducted, where the ADFI, ADG, FCR and hot carcass weight, cold carcass weight, dressing percentage were measured respectively. A completely randomised design was used in this experiment with seven animals per treatment. Before the trial, the lambs were vaccinated against brucellosis, pulpy kidney and treated for internal parasites. The inclusion levels of dried marula fruit peels had no significant impact (P>0.05) on the growth performance and carcass characteristics. This research has revealed that dried marula fruit peels can be used as a potential energy source for lambs without negatively affecting the growth and carcass characteristics of lambs at up to 10% inclusion level.
Open Access
Effects of dietary prickly pear (opuntia ficus indica l.) seed cake meal inclusion in a maize-cowpea diet on ROSS 308 broiler performance and carcass characteristics
(2023-10-05) Netili, Thuso; Fushai, F.; Netshipale, A. J.; Katla, E.
The aim of the study was to investigate the effects of graded inclusion of prickly pear oil seed cake (PPSC) in sprouted cowpea-maize diets for broilers. Diluent (0%PPSC) sprouted cowpea-maize grower and finisher diets, and the respective (10% and 12.5% crude fibre on DM basis) iso-nutrient, PPSC “’summit” grower and finisher diets were formulated and blended to constitute the test diets. Blended grower test diets contained calculated 0, 2.5, 5, 7.5, 8.75 and 10% PPSC, respectively denoted G0, G1, G2, G3, G4, and G5. Blended finisher test diets contained calculated 0, 3.1255, 6.25, 9.375, 10.9375%, 12.5% PPSC, respectively denoted F0, F1, F2, F3, F4, F5. Dietary nutrient profiles were benchmarked to respective commercial grower and finisher maize-soybean positive control (PC) diets. The trial used 504 Ross 308 broiler chicks reared in an open, deep litter house partitioned into 1.5 m long x 1.4 m wide steel framed, mesh wire pens, each holding 18 birds. Chicks fed on the same commercial starter (days 1-24) diet, after which they were assigned to grower (days 25-35), followed by finisher (days 36-42) experimental diets for a completely randomised experiment replicated four times. Birds had free access to feed and water. Feed intake (FI), live weight gain (LWG), and the feed conversion ratio (FCR) were evaluated, along with slaughter weight, carcass characteristics, visceral organ weights, and meat quality. Quadratic regression analysis revealed significant effects of dietary PPSC levels on grower phase intake (P = 0.044) and cumulative grower-finisher live weight gain (P = 0.04). During the grower phase, feed intake increased (P < 0.05) with PPSC inclusion until it matched the control diet at PPSC dietary level G3 and above (P > 0.05). The optimum dietary inclusion of PPSC for feed intake during the grower phase was estimated to be 1.74%. For the finisher phase, broilers on the F0-F2 PPSC inclusion levels had lower final (42-day) live weights compared to the control (P < 0.05). Live weight at and above F3 PPSC dietary inclusion was intermediate, similar to both the lower level PPSC dietary inclusion and the control (P > 0.05). A quadratic estimate of 4.58% dietary optimum PPSC inclusion was predicted for the cumulative live weight gain. Dressed carcass weight increased (P < 0.05) with dietary PPSC inclusion at and above the G3-F3 PPSC feeding regime, matching the control diet (P > 0.05). A quadratic estimate of 3.01% dietary optimum PPSC inclusion was predicted for carcass weight. The dressing percentage increased (P < 0.05) with dietary PPSC inclusion above the G2-F2 PPSC feeding regime, matching the control diet (P > 0.05). A quadratic estimate of 7.58% dietary optimum PPSC inclusion was predicted for dressing percentage. Broilers on the G5-F5 feeding regime had higher (P < 0.05) abdominal fat compared to those on no or lower PPSC feeding regimes, while broilers on the G4-F4 feeding regime had intermediate abdominal fat (P < 0.05). A quadratic estimate of 4.73% dietary optimum PPSC inclusion was predicted for abdominal fat. Quadratic regression analysis also showed significant effects of PPSC levels on scaled gizzard weight (P = 0.007). The optimal dietary inclusion of PPSC for scaled gizzard weight was estimated to be 4.39%. In conclusion, within the limitations of the recommended dietary fibre content, grower-finisher dietary PPSC inclusion upgraded the sprouted cowpea diets to match the standard diet in terms of grower phase feed intake, finisher phase live weight gain, slaughter weight, abdominal fat, and the dressing percentage, with the predicted optimum dietary inclusion level dependent on the broiler response variable. Based on the carcass yield, approximately 3 % was considered optimum dietary PPSC inclusion in sprouted-cowpea based broiler diets.
Open Access
Performance of ROSS 308 broilers on maize-sprouted cowpeas grower-finisher diets fortified with black soldier fly (hermatia illucens) larvae meal
(2023-10-05) Muleya, Thivhalitshi Thomas; Fushai, F.; Bhebhe, E.
The objectives of the study were to evaluate the efficacy of sprouted cowpea (Vigna unguiculata)- maize (Zea mays) grower and finisher broiler diets, and of 5%, versus 10% fortification of the diets with full-fat Black Soldier fly (Hermatia illucens) larvae meal (BSFLM). The trial used 360 -day-old Ross 308 broiler chicks reared in an open, deep litter house. Chicks were placed in 30 wire mesh experimental pens of 150 cm length × 144 cm width. Chicks were uniformly managed during the starter (21 days) phase, feeding on a commercial starter. The chicks received supplementary stress vitamins (Virbac© Samrand Business Park, Centurion, Pretoria, South Africa) during days 1-6. On day-22, sexed broilers were randomly allotted at 12 birds per pen in a 5 (diet) X 2 (sex) factorial arrangement with three replications per treatment. Grower phase (days 22-35) and finisher phase (days 36-42) dietary treatments were: 0% BSFLM sprouted cowpea negative control (NC) diets, positive control (PC) commercial diets, low (LF 5% BSFLM) and high (HF 5% BSFLM) fat sprouted cowpea diets with 5% BSFLM diets, and 10% BSFLM sprouted cowpea diets. Feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR) and mortality rates were measured on a weekly basis. Upon slaughter, the weight of the warm dressed carcass, carcass components, visceral organs and abdominal fat were measured while meat quality (pH, drip loss and meat colour) were evaluated. During the grower phase, broilers on the PC consumed more (p<0.05) feed and achieved higher weight gain (p<0.05) than those on the NC and LF 5% BSFLM diets. The PC birds achieved lower (p<0.05) FCR compared to broilers on the NC and HF 5% BSFLM. During the finisher phase, broilers on the PC consumed more (p<0.05) feed than those on the 10% BSFLM diet. Cumulatively throughout the grower-finisher phases, broilers on the PC had higher feed intake and weight gain (p<0.05) than on the NC and HF 5% BSFLM diets and attained higher (p<0.05) final live weight with lower (p<0.05) FCR compared to broilers on the NC. Male broilers consumed more (p<0.05) feed during the grower phase and by slaughter, with higher p<0.05) weight gain during finishing, which resulted in heavier (p<0.05) live weight at slaughter. There was no (p>0.05) sex * diet interaction on parameters for measuring the growth performance. Broilers on the PC had larger (p<0.05) breast weights compared to birds on the NC and the 10% BSFLM diets and had higher (p<0.05) thigh weights than those on all other treatments. Broilers on the PC had a larger (p<0.05) spleen than birds on the NC and the 5% BSFLM diets. The females had lower thigh and liver weights compared to the males (p<0.050). Birds on the 10% BSFLM had lower drip loss compared to those on the negative control (p<0.05). In conclusion, broilers fed the sprouted cowpea-maize diet without BSFLM had low feed intake, weight gain and high FCR during the growing phase, and these effects were vi cumulatively reflected at slaughter. Compared to the NC and PC diets, BSFLM fortification of sprouted cowpea-maize diets resulted in intermediate parameters for broiler growth performance. Based on the growth performance, it was concluded that dietary efficacy was in the order NC <5 % LF<5% HF< 10 % BSFLM < PC fortification.
Open Access
Effect of Avocado (Persea americana Mill) oil inclusion in the Tris-based extender on the quality of Boer goat semen stored at different temperatures
(2023-10-05) Moholola, Khomotso Cathrine; Mikasi, M. S.; Raseona, A. M.; Netshipale, A. J.
Semen extenders are chemical mediums used for preserving, and protecting spermatozoa against different shocks while processing, storing and transportation for use in artificial insemination (Raheja et al., 2018). There are challenges with the preservation of goat semen for Artificial Insemination (AI). Spermatozoa with poor viability were observed when goat semen was extended with egg yolk and skimmed milk because of the seminal plasma secreted by the bulbourethral gland (Cabrera et al., 2005). This study aimed to evaluate the effect of Avocado oil on Boer goats semen quality parameters during liquid storage (5˚C,17 ˚C and 24˚C). Semen samples collected from four matured Boer goats were pooled and Tris-egg yolk extenders were supplemented with Avocado oil at 0, 1, 2 and 3%. The samples were then stored at 5˚C,17 ˚C, 24˚C and several sperm parameters (motility, viability, morphology, and DNA fragmentation) were assessed at 0, 24, 48 and 72 h intervals. Results showed that the supplementation of Tris egg yolk with 1%, 2% and 3% Avocado oil improved total motility, progressive motility, morphology, and viability when stored at 5˚C for up to 72 hours and when stored at 17˚C for 24 hours. However, non-fragmented DNA improved when 3% of Avocado oil was added to the Tris egg yolk when kept at 5˚C from 24 hours. Therefore, it was concluded that the Boer goat spermatozoa quality could be preserved for 72 hours at 5˚C when adding 2% and 3% of Avocado oil to the Tris egg yolk extender. Semen with inclusions of Avocado oil in Tris-egg yolk can preserve Boer goat semen for 24 hours or less when stored at 17°C.
Open Access
Evaluation of Aloe vera (Aloe barbadensis linné) and Ginger (Zingiber officinale) as phytogenic supplements for broilers
(2023-10-05) Moalamedi, Masechaba; Fushai, F.; Netshipale, A. J.
The study investigated the potential of Aloe vera (Aloe barbadensis linné - AVE) and Ginger (Zingiber officinale - GNE) extracts as phytogenic supplements for broilers, as indicated by the growth, slaughter performance, visceral organ sizes, and meat quality broilers. A total of 480 Ross 308 broilers were housed in a deep litter open-sided house, stocked at 15 birds per 150 cm length × 144 cm width mesh-wire pen. During the starter period (days 1-22), the chicks were fed a diet containing 220 g kg-1 CP and 17.8 MJ ME kg-1. For the grower (days 23-36) and finisher (days 37-50) phases, the chicks were assigned to pens in a 2 (sex) × 4 (additive) factorial design, with two diets used for each phase: an antibiotic-free negative control (NC) diet and a positive control (PC) diet containing zinc bacitracin 15% granular at 500g/tonne plus 12% valinomycin sodium at 500g/tonne. Birds on the PC diet had access to clean drinking water only, while those on the NC diet received water without or with 2 mL/L of AVE or GNE. Birds on the GNE had small livers (33.5±1.37g), which suggested liver damage or a lower metabolic load. Birds on AVE had low (17.0±0.15g) abdominal fat, which indicated leaner growth. Males consumed more feed (145.5 ±2.74g) than the females (136.4±2.74g) during the finisher phase, and by slaughter (54.3±1.77 versus 52.6±1.77 g, respectively). The treatments affected the mean feed intake (132.7±2.27 - 149.5±2.27 g), weight gain (46.7±2.50 -77.7±2.50 g/bird/day), and FCR (3.4±0.14 - 2.1±0.14) across all growth phases, with the best performance recorded in birds on the PC. Females had higher percentage wings (4.8±0.18 versus 4.4±0.18 %) and breasts (33.9±0.96 versus 29.8 ±0.96 %) on the PC, compared to the NC treatment. In conclusion, the plant extracts did not improve broiler growth performance, carcass characteristics, and meat quality parameters at the 2 ml/L dosage.
Open Access
Effect of strain and skip a day technique on growth performance and carcass characteristics of broiler chickens
(2023-10-05) Makharamedzha, Murunwa; Bhebhe, E.
A skip a day feeding technique could mitigate the ever-increasing cost of feeds and the undesirable excessive adipose fat. The aim of this study was to determine effect of broiler strain (Ross 308 and Arbor Acres) and different regimes of the skip-a-day technique on growth performance and carcass characteristics of broiler chickens. A 2×3 factorial study was carried out to determine the growth performance and carcass characteristics of two broiler strains. Each treatment was replicated three times with 25 birds per replicate and thus a total of 450 unsexed chickens for this study. The treatments were as follows: (i) control-Adlibitum feeding, (ii) Treatment 1-birds were fed one day, and the next day was skipped, (iii) Treatment 2-birds were fed two days and the third day was skipped. Carcass weight, abdominal fat, mortality, and average weight gain were determined and recorded. Data was analysed using analysis of variance (ANOVA) for a 2×3 factorial experiment using the General Linear Model (GLM) procedures of Minitab 18 statistical software. Feed intake per bird per week (g) was significantly different between all three treatments (P<0.01) and followed a consistent yet unexpected pattern across strains with feeding regime zero (control pen)>FR0- Feeding regime one>FR1- Feeding regime two>FR2. Weekly feed intake per bird per week was significantly higher for FR0 (P<0.01) compared to FR1 and FR2 with the latter two treatments having non-significant means (P>0.05) and strain significantly affected feed intake where the Ross 308 strain consumed more feed than the Arbor Acres strain (P<0.05). Broiler strain as well as strain by skip-a-day level interaction effects were not significant for all the carcass parameters (P>0.05). The overall results of this study have shown that the Ross 308 and Arbor Acres broilers did not differ significantly in the body weight, body weight gain, feed intake, and abdominal fatness (P>0.05). However, the Ross 308 broilers strains consumed more feed than the Arbor Acres strain, but both strains converted the feed with the similar efficiency.
Open Access
Effects of molasses-enhanced fermentation and exogenous enzymes on the nutritive value of castor bean (Ricinus Communis L) oil cake for growing pigs
(2023-10-05) Ramukanda, Mulisa; Fushai, F.; Netshipale, A. J.
Castor bean (Ricinus communis L) is highly valued for its oil, which has diverse applications in the pharmaceutical industry. Castor bean oil cake (CBOC) contains high levels of protein, but contains highly toxic compounds that require proper processing before feeding to livestock. The aim of the study was to evaluate optimum solid fermentation for CBOC, and the effects on nutrient digestibility, nitrogen balance, or plasma metabolites of 10% of the optimally fermented CBOC (FCBOC) in a diet fortified with exogenous fibrolytic enzymes. In experiment 1, a micro-fermentation study was conducted to evaluate the optimum level of supplementary Voermol (Product V10257; molasses containing 33 g/kg CP, 300 g/kg moisture, 6-9.2 g/kg Ca, 0.8 g/kg P and, 9.5 MJ ME/kg), 75% BRIX 75) in relation to the period of anaerobic solid fermentation of the CBOC. The experiment followed a completely randomized, 4 (molasses level; 0%, 5%, 10%, and 15%) x 4 (fermentation days; 0, 4, 7, and 10-day) factorial design, replicated three times. The change in proximate and detergent fibre composition was evaluated, and the pH of the fermented CBOC (FCBOC) measured as an indicator of fermentation intensity and extent, which are key determinants of silage quality and anerobic stability. Highest (P<0.05) OM was observed in 5% Voermol, 4- day FCBOC, similarly (P>0.05) followed by 10% Voermol, 4% fermented FCBOC, and least (P<0.05) OM in 15% Voermol, 7- day FCBOC, followed in the increasing (P<0.05) order 10% Voermol, 4-day fermented FCBOC>15% Voermol, 4-day fermented FCBOC. Treatment effects on ash were inverse to the OM (P<0.05) The fat content decreased (P<0.05) with 7, and 10-day fermentation, while 15% Voermol inclusion decreased (P<0.05) the fat content. The lowest pH (3.89) was achieved with 5% Voermol inclusion and 7-day fermentation. In experiment 2, the effects of including 10% inclusion of the optimally (5% Voermol, 7-day fermentation) fermented FCBOC in the pig's diet, and the efficacy of fibrolytic enzymes were investigated. Experimental diets were a standard maizesoybean diet (0% FCBOC), and an iso-nutrient, 10% FCBOC diet, each with (+) and without (-) 500g/tonne of Ronozyme® WX CT (EC-3.2.1.8, 1000 FXU/g endo-1,4-β-xylanase). Eight growing (31.88 ± 1.63 kg live weight) male Large White x Landrace pigs in metabolic cages were assigned to diets in a randomized 2 (diet) x 2 (enzyme) factorial arrangement within a two balanced 4 (period) X 4 (diet) Latin squares. Each feeding period consisted of 9 days dietary adaptation, plus five days of feed intake measurement, and the total collection of faeces and urine, from which nutrient digestibility, and parameters of N balance (Nitrogen intake, Urine Nitrogen Output, Feacal Nitrogen Output, Total Nitrogen Excretion, Absorbed Nitrogen, Nitrogen Retention, Nitrogen Utilization, Biological Value Feed Protein , and Apparent N digestibility were calculated. Blood was collected by jugular venepuncture into 10ml serum vacutainers on the last day of each period, from which Glucose, Urea, Creatinine, total protein, albumin, globulin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, bilirubin, cholesterol and triglyceride were analysed. In conclusion, based on the depletion of organic substrates, intensity and extent of CBOC fermentation, optimum fermentation was considered to be through 5% supplementary Voermol and 7-day ensilage. The 10% dietary inclusion of the optimally fermented FCBOC was not detrimental to nutrient digestibility, nitrogen balance, or plasma metabolites, which were not affected by the fibrolytic enzymes.
Open Access
Effects of sprouting or roasting cowpeas (vigna unguiculata (L.) walp as protein source in diets for Southern African Windsnyer Type, Large White X Landrace and three -way crossbred growing pigs
(2023-10-05) Lubisi, Mfanuzile Welcome; Fushai, F.; Baloyi, J. J.
In poorly resourced settings, livestock feeding options are often narrowed to the affordable, readily available legume grains, and to their most convenient biological or thermal processing methods. The tolerance of different pig genotypes to toxic legume anti-nutritional factors and to the negative impact on dietary dietary nutrient availability may differ. The study aimed to determine the capacity of different local pig genotypes to utilise differently processed cowpeas (Vigna unguiculata (L.) Walp) as a dietary protein source during growth. Preliminary studies were conducted to determine the effective sprouting or roasting of cowpeas for feeding to growing pigs. In a sprouting experiment 1, cowpeas were soaked for 12 hours, open-sprouted over 1, 2, 3 and 4 days, with daily sampling, and the samples rapidly sundried to terminate the sprouting. In a roasting experiment 2, cowpeas were placed in an empty, preheated (150°C interior temperature) cast-iron drum, and roasted for 10, 15, 20, or 30 minutes, coincident with 55°C, 95°C, 105°C, and 130°C respective sample grain temperatures. The effectiveness of both processing procedures was evaluated by determining the in vitro dry matter digestibility (IVDMD) of the processed, compared to raw cowpeas. The IVDMD was estimated using a standard three-step (gastric, small, large intestines) in vitro pig digestion procedure, in a setup modified for micro (0.5 g) sample digestion within Ankom® 57 filter bags. Both the sprouting and roasting in vitro digestion were completely randomised, with 14 replicates per sample. Cowpea samples obtained at key sprouting or roasting points were analised for proximate and detergent fibre components, and for trypsin inhibitor activity (TIA), as auxiliary variable determinants of IVDMD. The steps 1-2 (gastricileal) IVDMD coefficient dropped (p<0.05) in the 2-day (0.78 ± 0.00486) and 3-day (0.77 ± 0.00486) cowpea sprouts, with equally high (p<0.05) step 3 IVDMD for 2-day and 3-day sprouts (0.13 ± 0.00605) compared to 1-day (0.07 ± 0.00605) and 4-day (0.10 ± 0.00605) sprouts. The total (steps 1-3) IVDMD increased (p<0.05) in 2-day (0.91 ± 0.00336) and 4-day (0.90 ± 0.00336) sprouts. Roasting did not affect steps 1-2 IVDMD. The 20-minute (105° C) roasting resulted in high (p<0.05) step 3 (0.17 ± 0.00734) and the total (0.98 ± 0.00449) IVDMD. The compartmental and total IVDMD, and quantitative change in chemical components and TIA indicated 4-day sprouting, and 20-minute (105° C) roasting were respectively most effective for cowpea processing, procedures which were subsequently used to process cowpeas in bulk for a metabolic, and a performance feeding trial. For the metabolic trial, raw (control) and the differently processed cowpeas were used to constitute iso-nutrient (15% CP, 14.17 MJ ME kg-1) maizebased grower pig diets. The metabolic trial used nine growing pigs, three each of Windsnyer (W), Large White (LW) X Landrace (LW) and the 3-way crossbred (W X LW X LR) genotypes. The pigs were inducted into the experiment at respective initial live weights 11.0 ± 1.15. 4 ± 1.15, and 12 ± 1.15 kg. Pigs were randomly allocated to diets for a factorial experiment within three balanced, 3 (genotype) x 3 (period) Latin squares with 12-day feeding periods split into sevenday adaptation, plus five days measurement of feed intake, and the total faecal and urine excretions. Metabolic size-scaled feed consumption was high (122.6 ± 3.01 g kg-1 Live weight (LW) 0.75) for the raw cowpeas, compared to the roasted cowpea diet (108.8 ± 3.01 g kg LW0.75) (p<0.05). On scaled bases, feed consumption was higher on the sprouted cowpeas compared to the raw diet (P<0.05). Sprouting and roasting both reduced the ash digestibility. Ash digestibility was lower (P<0.05) for LW x LR compared to W x LW x LR pigs. Genotype x Diet interaction was observed for ash, fat, ADF and NDF, however the main mean showed non-significant (P<0.05) for fat, ADF and NDF. Pig responses to the differently processed cowpeas were further evaluated in a 60-day growth trial which used a total of 36 animals, twelve male, 28-day weaned pigs of each of the W, LW X LR, and W x LW x LR genotypes (respective initial live weights 15.0 ± 2.3, 39.0 ± 1.4 and 37.0 ± 1.2 Kg). To balance the initial weights across treatments, pigs were blocked by weight within genotype, and randomly allocated within the weight blocks to the experimental diets for a 3 (genotype) X 3 (diets) factorial experiment replicated four times. The experimental diets were a standard, maize-soybean commercial pig grower (control) feed, and iso-nutrient (14.26 ± 1.2 MJ ME kg, 160.0 ± 2.1 g CP kg), roasted or sprouted cowpea-maize grower pig diets. Pig growth and slaughter parameters, visceral organ sizes, and plasma biomarkers of protein, energy utilization, and organ function were measured. Pig growth was different by genotype in the order LW x LR ≥ LW x LR x W > W (p<0.05). Feed intake ranked LW x LR ≥ LW x LR x W > W (p<0.05). Dietary treatments ranked control > sprouted cowpeas > roasted cowpeas diet (p<0.05). The FCR was similar (p>0.05) across the genotypes, but differed by diet in the order control (3.41 ± 0.551) < sprouted cowpeas (4.94 ± 0.551) ≤ roasted cowpeas (5.93 ± 0.551) diet (p<0.05). Back fat was thickest on the control diet (9.91 ± 0.321) compared to the other diets (p<0.05). The W pigs dressed inferior (p<0.05) compared to the other genotypes. Scaled on the metabolic weight, the liver and kidneys were large (p<0.05) in W pigs, and the kidneys enlarged (0.567 ± 0.0105 %) (p<0.05) in pigs on the roasted cowpea diet. The W x L x LR had low alkaline phosphatase activity (99.50 ± 6.090 U/L), W had low creatinine (44.94 ± 2.32 μmol/L) and cholesterol. (1.23 ± 0.0833 mmol/L); and LW x LR had low plasma total protein (69.20 ± 0.915 g/L). Pigs on the sprouted cowpea diet had high (p<0.05) urea (5.30 ± 0.255 mmol/L) and cholesterol (1.82 ± 0.0833 mmol/L). Albumin was low in pigs on the sprouted diet (35.58 ± 0.902 g/L) and on the roasted diet (35.60 ± 0.902 g/L), while alkaline phosphatase activity was high on the sprouted (110.92 ± 6.090 U/L) and the roasted (130.13 ± 6.090 U/L) diet (p<0.05). In conclusion, compartmental and total IVDMD, and quantitative change in chemical components and TIA indicated 4-day sprouting, and 20-minute (105° C) roasting were respectively most effective for cowpea processing. The observed genotype x diet interactions on N balance parameters confirmed genotype influences on the digestive capacity, and intermediary nutrient metabolism in pigs fed the raw, and differently processed cowpeas, which suggested unique adaptive digestive and metabolic traits among the experimental pig genotypes. The underlying mechanisms need further investigation. Roasting and sprouting of dietary cowpeas produced diets which supported similar, slower growth compared to the soybean-based diet, with higher FCR by pigs on the sprouted, compared to the roasted cowpea diet. Further research is recommended to evaluate the cost-effectiveness and practicality of cowpea sprouting or roasting in large-scale pig production systems.
Open Access
Effects of feeding sprouted Sorghum (Sorghum bicolor) diets fortified with exogenous enzymes on egg production of red and white amberlink layers
(2023-05-19) Muavha, Nkhumbuleni Remember; Fushai, F.; Netshipale, A. J. N.
The objective of the study was to investigate the effects of feeding sprouted sorghum (Sorghum bicolor) diets fortified with exogenous enzymes on egg production by Red and White Amberlink layers. Egg production by 216 Red and White Amberlink layers which were 16 weeks into production was evaluated over a six-week period. The layers were housed in a naturally ventilated battery house, placed in forty-eight 45 cm length × 45 cm width × 42 cm height cages, each stocked at 3 birds/cage. The birds were allocated to treatments in a randomised 3 (diets) X 2 (enzymes) X 2 (strain) factorial arrangement replicated six times. Experimental diets were Meadow Powerlay Late Lay (Product V16418) as a positive control (PC), and iso-nutrient (70 g/kg Crude Fibre, 130 g/kg CP, 5 g/kg Lysine), sprouted, and raw (negative control (NC) sorghum-soybean layer diets. A duplicate mix of each diet was fortified with 500 g/tonne of a custom multi-enzyme cocktail (xylanase Endo-1, 4-Beta-Xylanase (EC-3.2.1.8), 2440 U/kg, Endo-1, 3 (4)-Beta-Glucanase (EC-3.2.1.6), 304 U/kg, and 6-phytase (IUB 3.1.3.26), 1220 U/kg). Layers on the raw sorghum diet had low (P<0.05) feed intake. Interaction (p = 0.0038) of the layer strain, diet and enzyme occurred for the laying rate. Highest (P<0.05) laying rate was attained when the Red Amberlink layers were on the commercial diet with enzymes, and when White Amberlink layers were on the same diet without enzymes, similar (P>0.05) to when both strains were on the enzyme supplemented, sprouted sorghum diet. Lower (P< 0.05) laying rates were observed when both strains were on the raw sorghum, without (P>0.05) enzyme effect compared to other treatments. Laying rate in layers on the sprouted sorghum diet was not different (P> 0.05) from the commercial diet, and significantly higher (P< 0.05) raw sorghum-based diet with or without enzyme fortification. The net effect of treatments on laying rate was in the dietary order commercial feed >sprouted sorghum >raw sorghum (P<0.05). The Red Amberlink strain laid larger (P<0.05) eggs than the White strain. Expressed on both egg number and egg weight basis, the FCR were in the dietary order commercial feed >sprouted sorghum >raw sorghum (P<0.01). Strain*enzyme interaction occurred for egg weight (P<0.05), whereby the enzymes reduced (P<0.05) egg weight in Red Amberlink layers when on the sprouted sorghum diet, which was quantitatively similar on all other treatments, except for opposite, quantitative enzyme effect on White Amberlink layers on the commercial diet. Though inferior to the commercial diet, the comparative egg production and FCR largely supported replacement of the commercial, with sorghum diets, more so when the sorghum is sprouted. Treatment interaction on egg production and size suggested both beneficial and deleterious enzyme action, likely the effects of unique dietary chemical matrices.
Open Access
Efficient utilization of Macadamia oil cake based diets in ruminants
(2023-05-19) Mkhonto, Zinhle Debra; Baloyi, J. J.; Mikasi, M. S.
Ruminants and rumen bacteria form a symbiotic relationship. However, because of nitrogen (N) inefficiency, this interdependent relationship loses energy and protein. Strategic feeding of ruminants with diets containing non-conventional feedstuffs appears to be a promising way to enhance proficiency of protein and energy utilization in ruminants. Macadamia Oil Cake (MOC) can be classified among the non-conventional ingredients that can be included in animal diets, without resulting in any negative effects. The present study evaluated the utilization of MOC-based diets in ruminants. Eight Boer and eight Pedi bucks initially weighing an average of 34 ± 8.39 kg and aged 18 to 24 months were housed individually in metabolic cages (1.8 m × 0.58 m × 1.33 m) to measure nutrient intake, apparent digestibility, nitrogen (N) retention and microbial protein yield. The goats were balanced for breed and allocated in a completely randomized design (CRD) to four dietary treatments containing 0, 10, 15, and 20% MOC inclusion. Microbial protein yield was assessed using the urinary excretion of purine derivative (PD) allantoin method to estimate the efficient utilization of nitrogen in the MOC-based diets. The study was carried out for 21 days, beginning with 14 days for acclimatization and seven days for sample collection. MOC inclusion significantly affected (P˂0.05) the intake of ether extract (EE), neutral detergent fibre (NDF) and acid detergent fibre (ADF). However, the intake of dry matter (DM) , organic matter (OM) and crude protein (CP) were not significantly affected (P˃0.05) by MOC supplementation. Significant differences (P˂0.05) were observed for OM and EE apparent digestibility of MOC-based diets by goats. However, No significant differences (P>0.05) were found in the apparent digestibilities of DM, CP, NDF and ADF. Nitrogen (N) retention was not significantly affected (P>0.05). All goats had positive N-retention values. Urinary allantoin excretion differed significantly (P<0.05) within treatments and affected (P<0.05) microbial protein yield. To conclude, the results attained in this study imply that MOC does not affect apparent digestibility of DM, CP and N-retention but enhanced microbial protein yield. Therefore, MOC showed to be a promising protein source to be utilized in goat diets without significantly causing any adverse effects.NRF
Open Access
Effects of sprouted cowpea (vigna unguiculata) dietary inclusion with ronozyme ® ProAct supplementation on broiler performance
(2023-05-19) Mariba, Nancy; Fushai, F.; Bhebbe, E.
The study evaluated the efficacy of maize-sprouted cowpea (Vigna unguiculata) diets when fed with supplementary exogenous enzymes on the growth (live weight, live weight gain, feed conversion ratio) and carcass parameters of Ross-308 broilers. Cowpeas were screened for viable seed and sterilised by 30-minute immersion in 2% sodium hypochlorite aqueous solution. Germinated by 12-hour soaking in tap water prior to 4-day open-air, 2-hourly irrigated sprouting on steel screens, and rapid, hot sun-drying to 35% DM spread on black plastic sheeting laid on a concrete surface. Balanced [160 g CP kg-1 DM] cowpea-based grower and finisher diets were mixed at 0, 50, 100% with iso-nutrient respective commercial feed mixes (controls). Duplicates of the experimental diets were fortified with 200 g/tonne of Rononzyme ® ProAct (75,000 PROT units g-1 serine protease). Nine hundred chicks were randomly allotted at 30 birds/pen in a 3 (diet) x 2 (enzyme) factorial experiment replicated five times. Random sample (8 birds/pen) live weight were evaluated on a weekly basis. Treatments were subjected to the analysis of variance using Minitab Statistical package version 18 (Minitab, 2017). Treatment means were separated using Tukey’s test at 5% level of significance. The maize-sprouted cowpea inclusion rate had no effect (P>0.05) on feed consumption (g/b/d). Grower feed with 100 maize-sprouted cowpea inclusion had a significantly (P<0.05) lower live weight gain (45.0 g/b/d) (LWG) and consequently live weight at day 35 (LW35) compared to SCG0 and SCG50 which were not different. Enzyme fortification had no effect on all growth parameters in both grower and finisher phases. During the finisher phase, birds on maize-cowpea diets had significantly higher (P<0.05) feed consumption (g/b/d) compared to the control diet (SCF0). Diet SCF100 had the lowest (P<0.05) live weight at day 42 (LW42) compared to SCF0 and SCF50, and eventually had the highest feed conversion ratio (FCR). Cumulatively, grower-finisher (day 22-42) live weight gain (LWG22-42) was in the dietary order SCG0> SCG50>SCG100 (P<0.05). The feed conversion ratio (FCR22-42) was in the dietary order SCG0< SCG500.05) affect the abdominal viscera. The enzyme had no effect (P>0.05) on the slaughter parameters except the proportional weight (%) of the heart. The maize-sprouted cowpea diets resulted in a low value for the meat redness coordinate (a) (P < 0.05). The yellowness coordinate (b) was in the order SCG0-SCF0>SCG50-SCF50>SCG100-SCF100 (P < 0.05). Meat water holding capacity and the shear force were higher on the SCG0-SCF0 compared to the SCG100-SCG100-SCF100 feeding regime (P<0.05). In conclusion, dilution of the control with the sprouted cowpea diet reduced the live weight gain, feed efficiency ratio and carcass weight, and caused adverse effect on meat quality, with more adverse effects at the 100%, compared to the 50% dilution level. Adverse metabolic and physiological effects were v indicated by the enlargement of the liver and gizzard at the high inclusion of sprouted cowpea in broiler diets.
Open Access
Effects of exogenous enzymes on the nutritive value of macadamia spp. nut oil cake as a protein source for growing pigs
(2023-05-19) Rambau, Maemu Queen; Fushai, F.; Mikasi, M. S.
The current high cost and scarcity of the conventional stock feeds, and the predicted long-term impact of climate change on their production are major risks to sustainable animal production in the smallholder sector in South Africa. The present study investigated the nutritive value of Macadamia (Macadamia spp.) nut oil cake (MOC), and the efficacy of exogenous enzymes to enhance its value as an alternative protein source in growing pig diets. In an enzyme-screening in vitro study (experiment 1), 3-step (pepsin + pancreatin + Viscozyme) porcine digestion was employed to compare the digestive efficacy on MOC of a custom enzyme cocktail containing 3000 FTU g -1 6-phytase (IUB 3e1.3.26), 7270 U g -1 endo-1,4-Beta-Xylanase (EC-3.2.1.8), 300 U g -1 alpha amylase (EC-3.2.1.1), 6000 g -1 subtilisin protease (EC-3.4.21.62), 532 U g -1 endo-1,4-beta-glucanase (IUB 3.2.1.6), and Ronozyme® WX 2000 CT (UB 3.2.1.8 endo‐1,4‐β‐xylanase, 200FXU/g) . The experiment was performed in a completely randomized design with six replicates per treatment. In experiment 2, the experimental diets were a balanced, standard commercial maize-soybean diet, and an iso-nutrient, 10% MOC-maize-growing diet, each with a duplicate supplemented with 500g/tonne of the custom enzyme cocktail. Eight F1 Large White X Landrace piglets (15.3 ± 1.91 kg live weight (LW) were assigned to diets in a 2 x 2 factorial arrangement, in a duplicated, balanced 4 × 4 Latin square design. An 8-day feeding period was used in the Latin squares, consisting of 3 days adaptation, and 5 days of feed intake measurement, and the total collection of faecal and urine excreta. In vitro, the enzymes did not affect DM digestibility(P>0.05). Neither of the enzymes altered the partial gastric-small intestine (19.9-22-8), colon (21.3-22.8) and the total (41.2-44.4) IVDMD of MOC (0.05). In vivo, the 10% MOC diet had low (p<0.05) digestibility of crude protein, with no (p>0.05) effect on the digestibility of other chemical components. Scaled to the LW, 10% MOC dietary inclusion reduced (p<0.05) the NR. The NR was higher (p<0.05) on the 0%, compared to the 10% MOC diets only when the diets contained the exogenous enzymes. Scaled to the LW0.75, the 0% MOC dietary inclusion reduced (p<0.05) the NR. Dietary inclusion of MOC at 10% marginally reduced the digestibility of CP, and the NR. In v conclusion, the IVDMD of MOC was low, and not improved by fortification with fibrolytic exogenous enzyme cocktails. In vivo nutrient digestibility, and N balance responses to the 10% MOC diet were similar to a standard diet, which supported the 10 % dietary inclusion of MOC as an alternative protein source for weaned, fast-growing Large White pigs. A more potent exogenous proteinase and or carbohydrase enzymes could be effective tools to improve dietary efficacy and protein efficiency
Open Access
The effect of tris aloe vera (barbadensis miller) gel on chilled and frozen-thawed bull spermatozoa quality
(2023-05-19) Seshoeni, Kenny; Mikasi, M. S.; Netshipale, A. J.; Raseona, A. M.
Semen extenders protect sperm from cold shock, osmotic stress, and alterations in membrane fluidity and permeability plus provide energy substrates for sperm metabolism. Egg yolk is one of the most common additives of animal origin that are used for semen preservation, however, it has become a suspect for facilitating the transmission of diseases. Tris-aloe vera gel have several beneficial properties, such as anti-inflammatory, antioxidant, antiviral and antibacterial features. The aim of this study was to determine the effect of Tris-aloe vera gel (TAG) extender on the quality of bull spermatozoa. In experiment 1, the effect of Tris-Aloe vera gel extender was assessed after the semen was chilled at 5 0C in a refrigerator for different storage times up to 120 hours, and frozen in liquid nitrogen at -196 0C for 5 days in experiment two. Assessment was done for morphology, motility, and viability of bull spermatozoa. Semen samples were collected from four (4) Nguni bulls with proven fertility records, aged between 6 and 8 years kept at the University of Venda Experimental Farm under intensive farming practice. Collected semen samples were pooled and diluted at a ratio of 1:5 (semen to extender) in Tris-egg yolk (TEY) as a control and TAG at three different concentration levels 12%, 16% and 20% of Aloe vera gel (AVG). In experiment one, diluted semen samples were evaluated immediately after the extension using computer aided sperm analyzer (CASA) before storage at 5 0C, followed by sperm analysis after every 24 hours for 120 hours. In experiment two, freshly collected and diluted semen samples were cryopreserved and stored at (-196 0C) in LN2 for 5 days and evaluated thereafter. The results were subjected to the analysis of variance (ANOVA) for statistical analysis using a general linear model (GLM) procedures of Minitab 19 program. Tris-egg yolk extender (TEY) with 0% aloe vera gel was used as a control. In experiment one, it was found that TEY showed consistency in keeping motility at an average of 100% (p<0.05) after 120 h of chilling semen samples. Semen samples extended in Tris-aloe vera gel had a decrease in spermatozoa motility as storage time increased. Experiment two discovered that AVG can equally be used to substitute v egg yolk in tris-based extender and be able to cryopreserve Nguni bull semen for a period of 5 days, this is due to a fact that there was no significant difference (P<0.01) in spermatozoa progressive motility, from both TEY and TAGs post thaw. It was also found that morphological normal spermatozoa were above 80% post thaw. Semen extended in TEY shows a great deal of consistency in maintaining high spermatozoa viability throughout the chilling process.
Embargo
Effect of spermatozoa viability, culture receptacle, incubation, and intracytoplasmic sperm injection on vitro production of cattle embryoa using epididymal spermatozoa
(2022-07-15) Raseona, Andrea Motswetla; Barry, D. M.; Owiny, O. D.; Nedambale, T.L.
In an event of an unexpected death, injury, or inability of a bull to serve, spermatozoa can be harvested from the epididymides to enable the propagation of valuable germplasm from genetically superior males. Recovering bull spermatozoa from the epididymis of dead breeders presents the last opportunity to use the gametes and therefore, the need for the most efficient preservation and utilization of the recovered spermatozoa is paramount. One of the unique ways of preserving the male genetic material of cattle is the use of assisted reproductive technologies. The present study focused primarily on the production of in vitro cattle embryos using epididymal spermatozoa by firstly seeking the effective spermatozoa extender and preservation method, and secondly by assessing the effects of culture receptacles and incubation methods following intracytoplasmic sperm injection. In a series of experiments, ejaculated and epididymal spermatozoa were collected, chilled, cryopreserved, and used for in vitro embryo production. The viability of chilled bovine spermatozoa recovered from the epididymis stored at 5 °C for 24 h and diluted with Triladyl® or modified Ham’s F10 was assessed in the first experiment. The short-term preserved (120 h at 5 °C) ejaculated spermatozoa demonstrated a higher motility rate than epididymal sperm, however, epididymal spermatozoa harvested immediately after bull slaughter, extended with Triladyl® was found to have a higher motility rate (P < 0.05) than spermatozoa harvested 24 h post chilling of the epididymides at 5 °C diluted in modified Ham’s F10 culture media. A significant decline in viability was also demonstrated after 72 h of chilling at 5 °C with the least percentage of live cells detected with modified Ham’s F10 extended epididymal spermatozoa harvested 24 h post-mortem. Furthermore, less than 10% of acrosome defects were demonstrated across all the spermatozoa samples. It was concluded that refrigeration of epididymides at 5 °C for 24 h before the recovery of spermatozoa cells was able to sustain good spermatozoa motility when Triladyl® extender was used. The viability of frozen-thawed bull semen collected from the bull’s ejaculate and cauda epididymis was also evaluated. Similar to the observations on spermatozoa chilling in the first experiment, ejaculated spermatozoa had a higher post-thaw motility rate (P < 0.05) than epididymal sperm. However, no significant difference in post-thaw motility rate was demonstrated amongst epididymal spermatozoa recovered immediately and 24 h post-mortem (P > 0.05). The post-thaw percentage of acrosome defects, as well as the live cells, was found to be similar for both ejaculated and epididymal sperm. It was concluded that cooling of epididymides at 5 °C for 24 h before the recovery of spermatozoa cells was efficient in preserving post-thaw spermatozoa quality. In the third experiment, the success rates of in vitro embryo production using epididymal bull sperm, French semen straws as culture receptacle, and alternative incubation method was evaluated. The experiment was carried out as a completely randomised design arranged in a 3 x 2 x 2 factorial. The results demonstrated that short-term preserved (120 h at 5 °C) ejaculated spermatozoa produced a higher percentage of in vitro embryos compared to epididymal spermatozoa. However, no significant difference (P > 0.05), in blastocyst development was demonstrated between epididymal spermatozoa retrieved immediately and after 24 h post-mortem, extended in either Triladyl® or modified Ham’s F10, chilled for either 24 or 48 h. Additionally, no significant difference was demonstrated when comparing individual spermatozoa samples using French semen straws as culture receptacles, incubated in the goat doe vagina, versus a standard 5% CO2 incubator. It was concluded that in vitro embryos up to 8 days of development, cultured in French semen straws and incubated in the goat doe vagina, can be produced after fertilization with epididymal bull spermatozoa recovered immediately or after refrigeration of the epididymides at 5 °C for 24 h. Lastly, the study investigated the effect of using French semen straws as embryo culture receptacle and goat doe vagina as an alternative incubator, on in vitro embryo production following intracytoplasmic sperm injection with epididymal spermatozoa. The injected oocytes with epididymal spermatozoa recovered after bull slaughtering or after 24 hours post-mortem, cultured inside French semen straws or micro-droplets, had no difference in embryonic development rates (P > 0.05). Furthermore, when both the standard CO2 incubator and the goat doe vagina were used, no difference in embryo development stages was identified (P > 0.05), with the exception of the cleavage stage where the injected oocytes incubated in goat doe vagina showed lower rates (P < 0.05) as compared to those incubated in the standard CO2 incubator. It was concluded that fertilization and blastocyst development can be accomplished through intracytoplasmic sperm injection with cryopreserved bull epididymal spermatozoa recovered immediately or 24 h post-mortem, using French semen straws as culture receptacles and goat doe vagina as an alternative incubator.