This present study investigated the effect of bioactive peptide (BAPT) (BAPT) on the quality of ram semen during cryopreservation. Ram ejaculates were extended with Tris buffer supplemented with no antioxidants (as control group), 20 μg/mL BAPT (as BAPT20 group), 40 μg/mL BAPT (as BAPT40 group) and 60 μg/mL BAPT (as BAPT60 group). After cryopreservation, sperm quality including motility, vitality, the percentage of hypoosmotic swelling test (HOST)-positive spermatozoa and the percentage of intact acrosomes was assessed. Furthermore, the malondialdehyde (MDA) in seminal plasma and spermatozoa were analyzed, followed by the measurement of superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GSH-Px) levels in seminal plasma. After in vitro fertilization, the embryonic cleavage rates and development rates of different groups were analyzed to compare the developmental abilities of spermatozoa. The results showed that the post-thaw sperm motility was significantly higher in the BAPT60 group compared to those in the BAPT20, BAPT40 and control groups (P < 0.05). The percentage of live sperms significantly increased from 48.12 ± 2.35% for the BAPT20 group, 55.43 ± 2.16% for the BAPT40 group to 57.53 ± 3.15% for the BAPT60 group. The percentage of HOST-positive spermatozoa was significantly higher in the BAPT60 group than those in BAPT20, BAPT40 and control groups (P < 0.05). The MDA levels in seminal plasma and spermatozoa were significantly reduced with BAPT supplement (P < 0.05). Additionally, the SOD, CAT and GSH-Px levels in the BAPT experimental groups were significantly higher than those of the control group, which further indicated that BAPT significantly inhibit the reactive oxygen species (ROS) production during the cryopreservation of ram semen. Furthermore, the embryonic cleavage rates and development rates of the BAPT40 and BAPT60 groups were significantly increased in comparison with the BAPT20 and control groups (P < 0.05). In conclusion, BAPT improved the ram sperm quality via inhibiting the ROS production during cryopreservation, and could be applied as a promising supplement for ram semen cryopreservation.

中文翻译：

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生物活性肽对公羊精液冷冻保存的影响

本研究调查了生物活性肽 (BAPT) (BAPT) 在冷冻保存期间对公羊精液质量的影响。用不含抗氧化剂的 Tris 缓冲液（作为对照组）、20 μg/mL BAPT（作为 BAPT20 组）、40 μg/mL BAPT（作为 BAPT40 组）和 60 μg/mL BAPT（作为 BAPT60 组）延长 Ram 射精。冷冻保存后，评估精子质量，包括活力、活力、低渗肿胀试验（HOST）阳性精子百分比和完整顶体百分比。此外，分析精浆和精子中的丙二醛 (MDA)，然后测量精浆中的超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT) 和谷胱甘肽过氧化物酶 (GSH-Px) 的水平。体外受精后，分析不同组的胚胎卵裂率和发育率，比较精子的发育能力。结果显示，与BAPT20、BAPT40和对照组相比，BAPT60组解冻后精子活力显着提高（P < 0.05）。活精子的百分比从 BAPT20 组的 48.12 ± 2.35%、BAPT40 组的 55.43 ± 2.16% 到 BAPT60 组的 57.53 ± 3.15% 显着增加。BAPT60组HOST阳性精子百分比显着高于BAPT20、BAPT40和对照组（P < 0.05）。补充 BAPT 后精浆和精子中的 MDA 水平显着降低（P < 0.05）。此外，SOD、BAPT实验组CAT和GSH-Px水平显着高于对照组，进一步说明BAPT显着抑制公羊精液冷冻保存过程中活性氧(ROS)的产生。此外，与BAPT20和对照组相比，BAPT40和BAPT60组的胚胎卵裂率和发育率显着提高（P <0.05）。总之，BAPT通过抑制冷冻保存过程中活性氧的产生来提高公羊精子质量，可作为一种很有前途的公羊精液冷冻保存补充剂。与BAPT20和对照组相比，BAPT40和BAPT60组的胚胎卵裂率和发育率显着提高（P < 0.05）。总之，BAPT通过抑制冷冻保存过程中活性氧的产生来提高公羊精子质量，可作为一种很有前途的公羊精液冷冻保存补充剂。与BAPT20和对照组相比，BAPT40和BAPT60组的胚胎卵裂率和发育率显着提高（P < 0.05）。总之，BAPT通过抑制冷冻保存过程中活性氧的产生来提高公羊精子质量，可作为一种很有前途的公羊精液冷冻保存补充剂。