Objective: To characterize Venda cocks semen, find a suitable short-term diluted semen storage temperature, find a suitable cryopreservation cryoprotectant and to investigate cryoprotectant toxicity. Methods: Semen was collected from six Venda cocks and evaluated macroscopically for semen volume, pH and sperm concentration. Microscopic sperm characteristics examined included were total motility (rapid, medium and slow) progressive and non-progressive motility. Velocity characteristics included curvilinear and straight-line velocity, average path velocity, linearity, straightness, wobble, amplitude of lateral head displacement and beat cross frequency. Results: Results showed that the average semen volume was 0.3 ± 0.1 mL, the pH 6.9 ± 0.4 and the sperm concentration (6.8 ± 79.8) × 109/mL. A positive correlation was observed between body weight and semen volume (r = 0.38). Similarly a significant difference between the initial sperm total motility (TM%) of 87.5 ± 8.6 and samples stored for 24 h at 5 °C (55.0 ± 8.0) and 25 °C (30.6 ± 6.1) was recorded. The percentage live and normal sperm was 87.0% and 93.5% (P < 0.05) respectively. The TM% recorded was significantly different in samples supplemented with DMSO (46.0 ± 8.3), ethylene glycol (EG) (45.0 ± 12.2) and propanediol (PND) (21.8 ± 10.4), following thawing. Detailed velocity values showed consistent differences between the raw and cryoprotectant-free semen samples. Conclusions: In conclusion, the Venda cock semen was subsequently found to have a higher TM% when stored in vitro at 5 °C. DMSO and EG were found to be suitable for the cryopreservation of Venda cock semen

Cryopreservation has been reported to damage approximately 40-50% of viable sperm in bull semen. The present study was undertaken to assess the cryo-effectiveness of glycerol (GLY), ethylene glycol (EG), dimethyl sulfoxide (DMSO) and propylene glycol (PND) as cryoprotectant during the cryopreservation of Nguni bull semen. Semen was collected from 18 Nguni bulls and evaluated macroscopically and microscopically for sperm parameters. Thereafter, the semen samples were diluted with egg-yolk citrate extender supplemented with either 12% GLY or DMSO or EG or PND cryoprotectant. Semen samples were loaded into straws and placed into a controlled rate programmable freezer and stored in a liquid nitrogen tank. Following semen thawing, artificial insemination (AI) was done on synchronized Nguni cows. The in vitro fertilization (IVF) was conducted on cow's oocytes to test the fertilizing ability. Data was analyzed with the aid of ANOVA. A significant difference (p < 0.05) was recorded between fresh total sperm motility rate (94.7 ± 2.6%) and frozen-thawed sperm total motility rate with GLY (77.8 ± 11.0%), EG (20.4 ± 10.1%), DMSO (15.7 ± 11.9%) and PND (11.2 ± 11.3%). Interestingly, a positive correlation between total sperm motility and pregnancy rate (r = 0.42) was recorded. However, a negative correlation of Nguni sperm parameters with IVF (r = -0.53) was obtained. The freezing-thawing process did reduce the Nguni sperm total sperm motility percentage.

South Africa recognizes the value of indigenous breeds such as Potchefstroom Koekoek, Boschveld, Ovambo, Venda, Naked Neck, and nondescript village chickens. Indigenous chickens support sustainable food systems, improve nutrition, and enhance livelihoods in rural communities, thereby contributing to the United Nations’ Sustainable Development Goal (SDG) 2 on Zero Hunger. These breeds are not only vital to rural farmers for food production, income generation, and subsistence but also provide rural farmers with cheap nutritious protein such as eggs and meat for household consumption. Moreover, they are preferred by rural farmers because they are relatively affordable to produce, can withstand harsh environmental conditions amid accelerated climate change compared to exotic breeds, and require less/no feed supplementation. However, despite the numerous advantages of keeping these chickens, it has been found that they are mostly in danger of extinction due to evolving production methods that favor exotic breeds. Therefore, understanding their extinction status, different implications for conserving their genetic material, challenges encountered, and future approaches to rescue these breeds remain vital. Hence, the aim of this systematic review was to assess the extinction status, challenges, and conservation approaches for these breeds. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were utilized to search for suitable articles addressing the objective of the current review. Research articles were grouped and evaluated for eligibility, and the data from the Domestic Animal Diversity Information System database were used. Records such as duplicates of studies addressing origins, phenotypic and genetic diversity, the conservation of indigenous chickens, semen cryopreservation of indigenous chickens, climate change effects on indigenous chickens, and the use of extenders with exotic chickens and other chicken types, reports in other languages, and reports that were inaccessible were excluded. Articles addressing origins, phenotypic and genetic diversity, the conservation of indigenous chickens, semen cryopreservation of indigenous chickens, climate change effects on indigenous chickens, and the use of extenders with indigenous chickens were included in this review. The keywords used to search articles online were as follows: South African indigenous chicken; extension status; conservation; genetic resources; genetic markers; effective population size; inbreeding; and characterization. This systematic review found that there is less information in the Domestic Animal Diversity Information System regarding South African indigenous and village chickens, suggesting a lack of reporting in this system. Moreover, our review confirmed that most South African indigenous chickens are threatened and, hence, require interventions such as assisted reproductive technologies and other strategies in order to improve efficiency.

The objectives of this study were to evaluate the properties of sperm motility and morphology under induced oxidative stress, compare the antioxidant capacity of dithiothreitol (DTT) and glutathione (GSH) following the cryopreservation of Large White boar semen, investigate the ability of cryopreserved Large White boar semen to fertilize the matured gilts oocytes and compare the efficacy of DTT and GSH antioxidants in improving the oocyte fertilization by cryopreserved Large White boar semen. The semen was collected from three Large White boars (ten ejaculates per boar) and transported (37 °C) to the laboratory. Semen freezing extenders were supplemented with 5 mM DTT, 5 mM GSH and a combination of 2.5 mM DTT + 2.5 mM GSH. A liquid nitrogen vapor method was used to freeze boar semen. Gilts’ ovaries were collected from the local abattoir and transported (37 °C) to the laboratory. The slicing method was used to retrieve the oocytes from the ovaries. Fresh semen and frozen-thawed semen were used for in vitro fertilization (IVF). For frozen-thawed semen, four treatments (control, 5 mM DTT, 5 mM GSH, and a combination of 2.5 mM DTT + 2.5 mM GSH) were used during IVF in order to evaluate the fertilizing ability of the antioxidants. The supplementation of 5 µM DTT to H₂O₂-treated semen significantly improved progressive motility (PM) by 14.82%. A combination of 2.5 mM DTT + 2.5 mM GSH treatment reduced percentage of sperm total motility (TM) and rapid motility (RAP) following thawing (p < 0.05). Fresh semen and a combination of 2.5 mM DTT + 2.5 mM GSH treatment recorded a higher percentage of zygotes with polyspermy (p < 0.05). The control treatment numerically recorded a high percentage of zygotes with 1 PN, while the 5 mM DTT treatment recorded a high percentage of zygotes with 2 PN.

Smallholder beef cattle farms in South Africa have had low reproductive performance, which has been associated with management practices. Considering current farm management practices, a multi-stage selection study was conducted to assess reproductive performance as defined by pregnancy rate, fetal and calf losses, calving interval and days open to benchmark reproductive performance. Data were collected twice, in autumn (March–May) for pregnancy diagnosis and in spring (September–November) for monitoring of confirmed pregnancies. Overall, 3694 cow records from 40 smallholder herds were collected during 2018 and 2019 breeding seasons from five provinces. The preferred 25th quartile described target performance and GLIMMIX procedure determined associations between management practices and performance. Smallholder farms on average recorded 50% pregnancy rate and 12% fetal and calf losses with 304 and 608 days open and calving interval, respectively. The derived target benchmarks for pregnancy rate, fetal and calf losses, days open and calving intervals in smallholder farms were 54%, 1.4%, 152 and 425 days, respectively. Reproductive performance was associated with no knowledge of body condition scoring before breeding, culling of old and non-productive cows, record keeping and low bull to cow ratio (p < 0.05). The performance benchmarks implied that industry averages may be improved if sustainable management services are provided through extension and advisory services.

The domestic pig breeds are in danger of extinction whereas the erosion of their gene pool is a serious concern because they significantly contribute to the rich biodiversity. Overall aim of this study was to determine the protocol for preserving the semen of the Windsnyer boars for conservation. A total of 18 ejaculates (6 replications/boar) were collected from three Windsnyer boars of proven fertility with the use of hand-gloved approach method, twice per week. Boars semen were pooled and extended with Beltsville Thawing Solution [(BTS) IMV Technologies, France], held at 18°C for 3 hours and centrifuged. The sperm pellet was re-suspended with Fraction A (20% egg yolk + BTS) and cooled at 5°C for 1 hour. Following cooling, semen was divided and diluted into different cryoprotectants (ethylene glycol, glycerol, propanediol, ethylene glycol + glycerol + propanediol) at equal contribution to make the total concentrations [4, 8, 12 and 16% and the 0% (control; without cryoprotectant)] and loaded into 0.25 mL straws. Two cryopreservation methods (liquid nitrogen vapour and controlled rated) were used to cryopreserve the semen straws. Semen straws were thawed at different temperatures (5, 18, 37 and 40°C) and evaluated for sperm motility, viability, and morphology traits. Post-thawed sperm total motility (36.0±5.3) and live normal sperm (49.5±8.3) percentages were recorded to be higher in the treatment supplemented with 16% glycerol (P<0.05). The highest sperm total motility percentage was recorded at 40°C (26.8±3.2) thawing temperature for liquid nitrogen vapour treatment (P<0.05). In conclusion, 16% glycerol was found to be the suitable cryoprotectant concentration for semen cryopreserved with liquid nitrogen vapour method and thawed at 40°C.