Yotov Stanimir, Fasulkov Ivan, Atanasov Anatoli, Kistanova Elena, Sinapov Branimir, Ivanova Boyana, Yarkov Dobri, Zaimova Darina
Department of Obstetrics, Reproduction and Reproductive Disorders, Trakia University, 6000 Stara Zagora, Bulgaria.
Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
Animals (Basel). 2023 Mar 1;13(5):896. doi: 10.3390/ani13050896.
This study aimed to evaluate the effect of the ovarian status and steroid hormone concentration on the day of TAI on the reproductive performance of dairy cows subjected to estrus synchronization treatment and timed artificial insemination with sexed semen. Seventy-eight cyclic Holstein cows pre-treated with PGF2α-GnRH were divided in two groups-I (Preselect-OvSynch, = 38) and II (OvSynch+PRID-7-day+eCG, = 40)-and inseminated with sexed semen. The presence of preovulatory follicle (PF) with or without corpus luteum (CL), the PF diameter, the estradiol (E) and progesterone (P) concentrations on the day of TAI, the pregnancy rate (PR) and embryo loss were determined. On the day of TAI, 78.4% of all the pregnant cows presented a PF (mean size 1.80 ± 0.12 cm) without CL, low P (0.59 ± 0.28 ng/mL) and high E (12.35 ± 2.62 pg/mg) concentrations. The positive correlation between the size of the PF and the level of E in the pregnant cows from group II was stronger than that of group I (R = 0.82 vs. R = 0.52, < 0.05). The pregnancy rate on day 30 (57.5% vs. 36.8%) and day 60 (50% vs. 26.3%; < 0.05) and the embryo losses (13% vs. 28.5%) showed better effects of treatment in group II. In conclusion, the ovarian status and the steroid hormone concentration on the day of TAI influence the pregnancy rates of dairy cows subjected to estrus synchronization and timed artificial insemination with sexed semen.
本研究旨在评估定时人工授精（TAI）当天的卵巢状态和类固醇激素浓度对接受发情同步处理并使用性控精液进行定时人工授精的奶牛繁殖性能的影响。78头经PGF2α - GnRH预处理的周期性荷斯坦奶牛被分为两组——I组（预筛选 - 发情同步，n = 38）和II组（发情同步 + PRID - 7天 + eCG，n = 40），并使用性控精液进行授精。测定了有无黄体（CL）的排卵前卵泡（PF）的存在情况、PF直径、TAI当天的雌二醇（E）和孕酮（P）浓度、妊娠率（PR）和胚胎损失情况。在TAI当天，所有怀孕奶牛中有78.4%出现了无CL的PF（平均大小1.80±0.12厘米），P浓度低（0.59±0.28纳克/毫升），E浓度高（12.35±2.62皮克/毫克）。II组怀孕奶牛中PF大小与E水平之间的正相关性强于I组（R = 0.82对R = 0.52，P < 0.05）。第30天（57.5%对36.8%）和第60天（50%对26.3%；P < 0.05）的妊娠率以及胚胎损失（13%对28.5%）显示II组的处理效果更好。总之，TAI当天的卵巢状态和类固醇激素浓度会影响接受发情同步和使用性控精液进行定时人工授精的奶牛的妊娠率。
