Laboratory of Theriogenology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan.
Laboratory of Clinical Veterinary Medicine for Large Animal, School of Veterinary Medicine, Kitasato University, Towada 034-8628, Japan.
J Reprod Dev. 2022 Aug 1;68(4):295-298. doi: 10.1262/jrd.2022-006. Epub 2022 May 30.
We investigated the optimal timing of artificial insemination (AI) for achieving pregnancy according to the onset/end of estrus detected by an accelerometer system in Holstein cattle. The conception rates of conventional semen were used as a reference. The conception rate from AI of sex-sorted semen was higher at -4 to 4 h (57.1%) from the end of estrus than those at -12 to -4 h (37.7%) and 12-20 h (30.3%), whereas AI at 4-12 h showed an intermediate conception rate (47.4%). Conversely, conception rates were similar in AI performed between 0 and 32 h from the onset of estrus. Regarding conventional semen, the interval from the onset and end of estrus did not affect conception rates. The present results suggest that the time of the end of estrus is the better indicator of optimal AI timing for sex-sorted semen than the onset of estrus.
我们研究了根据荷斯坦奶牛发情期检测加速计系统的开始/结束来确定人工授精（AI）的最佳时间，以实现妊娠。使用常规精液的受孕率作为参考。与发情开始后 0-32 小时内进行 AI 相比，发情结束后 -4 至 4 小时内进行的性别筛选精液 AI 的受孕率更高（57.1%），而发情结束后-12 至-4 小时（37.7%）和 12-20 小时（30.3%）的受孕率较低，而发情后 4-12 小时的受孕率则处于中间水平（47.4%）。相反，发情开始后 0 至 32 小时内进行 AI 的受孕率相似。对于常规精液，发情开始和结束之间的间隔并不影响受孕率。本研究结果表明，发情结束时间是性别筛选精液最佳 AI 时间的更好指标，而不是发情开始时间。
