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.

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.

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.

The study aimed to determine the efficacy of different semen extenders and in vitro storage periods on the Windsnyer boar sperm quality equilibrated at 18°C. Ejaculates (n = 18) from three Windsnyer boars of known fertility were evaluated for macroscopic traits, pooled, and then allocated for extension in Beltsville Thawing Solution (BTS) and Kobidil⁺ extender. Diluted semen was stored at 18°C and evaluated at 0, 4, 8, 12, 24 and 48 h post collection for sperm microscopic traits. Semen diluted with BTS extender maintained the highest live normal sperm percentage at 4 (63.0 ± 10), 8 (49.6 ± 8.7), 12 (38.0 ± 12.6), 24 (22.6 ± 10.7) and 48 (12.0 ± 10.7) hours, when stored at 18°C (p < .05). The BTS extender maintained the sperm total motility greater than 40% up to 24 h at 18°C as compared to the other semen Kobidil⁺ extender treatments (p < .05). Average <5% of sperm abnormalities were recorded over 48 h of in vitro boars semen storage irrespective of the semen extenders. Windsnyer boars sperm quality was maintained over 48 h when the semen was diluted with BTS and stored at 18°C.

The plants’ extracts have recently emerged as a cheap and natural source of additives to preserve and enhance sperm functions during the cryopreservation process. Extracts from plants are reported to be the main sources of natural antioxidants with lower cytotoxicity as compared to therapeutic antioxidants. The numerous and valuable plant properties, such as antioxidants, antimicrobial, antiviral, anti-inflammatory, and antiparasitic, have been linked to plant extracts. Numerous plant extracts from different species have been used as preservatives for livestock semen cryopreservation. During these processes, the extracts are added to the semen extender in different doses to keep the sperm motile and viable throughout the cryopreservation, including during pre-freezing, equilibration, and post-thawing. The sperm quality parameters can be improved by adding these natural compounds that exert protection against bacteria and reactive oxygen species scavengers in semen extender. Although the application of plant extracts as preservatives for semen storage is still emerging, their potential is promising. They represent natural and economically viable alternatives to the conventional additives currently employed for semen preservation. This review focuses on the aspects related to plant extracts and their role during cryopreservation of semen from domesticated livestock species.

Assisted reproductive technologies are critical in the preservation of gametes from endangered species. As a result, cryobanking is critical in reproduction facilities for the gametes conservation of endangered species for future use. Furthermore, cryobanking allows for the preservation of genetic variability through biotechnological reproduction programs. If oocyte cryopreservation is successful, the timing of in vitro maturation and subsequent to in vitro fertilization (IVF) will be possible. Cattle oocytes are very sensitive to cryopreservation due to their complex structure, and they are also very sensitive to chilling, which can harm their viability. During the cryopreservation process, sperm membrane proteins and carbohydrate composition change, sperm membrane structure is disrupted, and sperm viability is reduced. Extenders are frequently required during cryopreservation, for improving sperm cryopreservation technologies and is therefore necessary to have a thorough understanding of the properties of the extenders. Extenders have been enriched with antioxidants such as Glutathione to protect sperm motility and integrity from oxidative damage and the reactive oxygen species produced during cryopreservation can be neutralized using antioxidants.