Inhibiting oxidative stress is key for ensuring sperm motility during semen cryopreservation. The aim of this study was to investigate the effect of adding alpha-lipoic acid (ALA) as an extender in rooster semen cryopreservation. Different concentrations of ALA were added to the frozen diluent of rooster semen; subsequently, computer-aided semen analysis was used to determine membrane functional integrity, acrosome integrity, antioxidant capacity (based on T-AOC, GSH-Px, SOD, CAT, and MDA contents), and mitochondrial integrity. The frozen sperm ultrastructure was observed using transmission electron microscopy. The results showed that the addition of different concentrations of ALA partially to greatly improved the quality of frozen sperm; in particular, 8 μg/mL ALA significantly improved multiple parameters of sperm quality, including sperm motility and antioxidant enzyme activity, after freeze-thaw. The results of this study provide empirical and theoretical support for effective rooster semen cryopreservation and can inform the development of new protective agents in the field of livestock reproduction.

Sperm cryopreservation is of great importance for the poultry industry but still needs to be optimized. The high susceptibility of poultry sperm to cryodamage leads to low fertility rates after cryopreservation. Therefore, the present study aimed at evaluating the effect of including a cryoprotectant, dimethylacetamide (DMA), in the chicken semen freezing extenders at a final concentration of 3%, 6%, or 9% on the post-thawed sperm motility, quality, antioxidant biomarkers, anti-freeze gene expression, and fertilizing ability. Results showed that the total motile sperm, progressivity, and viability were quadratically increased (p < 0.05) in the 6% DMA group. The antioxidant enzyme activity and lipid peroxidation were negatively (p < 0.05) affected by the increase in DMA concentration. Furthermore, some anti-freeze-associated genes such as heat shock protein 70 (HSP70) and ras homolog family member A (RHOA) were linearly and quadratically down-regulated (p < 0.05) with the high concentration of DMA. Finally, the fertility and hatchability rates did not indicate statistical differences between DMA groups. It can be concluded that using the low concentration of 3−6% DMA in the freezing semen extender is preferable to obtain acceptable results in the post-thawed sperm quality and fertility.

It is important to inhibit oxidative stress to maintain sperm motility during cryopreservation. The present study was performed to investigate the effects of supplementing oligomeric proanthocyanidins (OPC) and bamboo leaf flavonoids (BLF) or their combination as an extender for Simmental bull semen freezing. OPC, BLF, or their combination were added to the frozen diluent of bovine semen. Afterwards, computer-assisted semen analysis (CASA), detection of membrane functionality, acrosome integrity, mitochondrial integrity, CAT, SOD, GSH-PX, MDA, and ROS were conducted. The results showed that adding 50 mg/L OPC or 4 mg/L BLF could improve the quality of frozen sperm. Compared with 50 mg/L OPC alone, the combination of 50mg/L OPC and 2 mg/L BLF significantly increased the kinematic parameters of sperm, and sperm CAT, GSH-PX and SOD levels (p < 0.05), whereas the MDA of sperm was decreased (p < 0.05). These results indicated that compared to the addition of 50 mg/L OPC alone, a combination of 50 mg/L OPC and 2 mg/L BLF could further improve the quality of frozen semen. The results could provide theoretical data support for the development of a new protective agent and are significant for the cryopreservation of bovine semen in the future.

The aim is to optimize the dimethylacetamide (DMA) straw freezing technology of Black silkies rooster semen through the handy patent equipment, screening the formula of freezing basic extender and optimizing the DMA addition method, and then by comparing the fertility of DMA straw frozen semen with the pellet frozen semen. After the DMA straw freezing technology is optimized, it is extended to the Youxian Partridge drake semen. The result showed that the frozen sperm motility of Lake and Ravie (LR) group is 64%, the fertility 49.57% and the hatchability 91.52%, all of which are superior to those of FEB, Beltsville Poultry Semen Extender (BPSE) and Lake (P < 0.05). The sperm motility of adding DMA stock solution is 59%, which is superior to adding DMA directly into diluted semen (P > 0.05). The fertility and hatchability of DMA straw group are 77.61% and 92.30%, respectively, and it is significantly higher than those in the pellet group (P < 0.01; P < 0.05). The fresh drake sperm motility of induction collection method is 71%, the massage collection method 61% and the frozen drake sperm motility of induction 33% while the massage 19%. The fertility of frozen drake semen group is 85.93%, while that of the fresh semen group is 88.17%. The frozen drake semen fertility of the highest batch is 93.8%. In conclusion, the world\'s advanced fertility of frozen semen can be obtained both in the chicken and drake through the optimized DMA straw freezing technology and the method of screening freeze-resistant individuals.