Cryopreservation is currently an essential technique in reproductive technologies that is used for the extended preservation of genetic material. Vitrification has become the industry’s standard cryopreservation technique for cattle oocytes and embryos. The current results of this technology, however, are still not good in terms of viability, fertilisation capacity, embryo development, or pregnancy. The oocytes’ susceptibility to freezing is associated with significant changes in the structures, functioning of the oocytes, and cryoinjury, which is harmful to the survival of cells and their subsequent growth. The effectiveness of producing embryos with in vitro techniques utilising vitrified cattle oocytes rarely exceeds 30–40%. A significant number of vitrified oocytes do not successfully develop into the embryo stage following in vitro fertilisation and culture. This review focuses on issues related to oocyte cryopreservation, ways to overcome them, and how to enhance the vitrified oocyte fertilisation process.

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 p0.05) 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) (p0.05). 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

Giraffe populations have declined by 30–40% over the past three generations, resulting in local extinctions in many habitats. In contrast, the South African subspecies is stable and subject to culling in some reserves, creating opportunities for post-mortem gamete recovery to support conservation. This study evaluated the preservation potential of epididymal sperm collected from South African giraffe bulls. Paired testes from 12 bulls were collected post-mortem and placed at 5°C mobile fridge from the Sandveld Nature Reserve. Sperm was retrieved from the cauda epididymides by slicing immediately (n = 4), four hours (n = 4), six hours (n = 2), and eight hours post-mortem (n = 2). Samples were extended in tris-egg yolk (TEY) or Ark Biotechnology's proprietary flush buffer for liquid preservation at 4°C and cryopreservation. Sperm quality was assessed microscopically, and motility parameters were analyzed using two-way ANOVA. Sperm quality was maintained up to six hours post-mortem, with total motility exceeding 75%. A sharp decline occurred at eight hours (<20%). After 72 h at 4°C, Ark buffer preserved higher motility (62 ± 3.43%) than TEY (44 ± 3.21%). In contrast, TEY produced superior cryopreservation outcomes, with post-thaw motility of 70% immediately and 65 ± 2.55% after two hours, compared to Ark biotech buffer (25% and 0%, respectively). Epididymal sperm from giraffes can be effectively recovered up to six hours post-mortem without loss of quality. Ark Biotechnology's flush buffer is advantageous for short-term liquid preservation, while TEY is better suited for cryopreservation.

Ruminant landraces that are locally adapted have become crucial for sustainable farming considering climate change. This study sought to evaluate the commencement of reproductive capability of Bapedi, Namaqua-Afrikaner and Zulu ram lambs. Data were collected from a total of 21 ram lambs (7/breed) starting from 3–8 months of age. From four months of age, the scrotal circumference of rams was measured using a flexible tape and it was found that it differed significantly between breeds (P < 0.05). Blood was collected from the jugular vein using a 21-gauge needle and red cap vacutainers. Blood serum testosterone levels were obtained using a competitive enzyme immunoassay. It was found that Bapedi, Namaqua-Afrikaner and Zulu ram lambs had similar blood serum testosterone levels (P > 0.05). At 7 months, semen was collected using an electro-ejaculator and analysed using a Sperm Class Analyser©. There were significant differences found in semen quality between the studied breeds for various semen parameters (P < 0.05). There was a weak positive correlation between blood serum testosterone and scrotal circumference (r = 0.30). Conclusively, this study highlights the importance of characterisation for the conversation of landrace breeds.