Kasimanickam R, Hall J B, Currin J F, Inman B, Rudolph J S, Whittier W D
Department of Large Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA 24061, USA.
Reprod Domest Anim. 2010 Jun;45(3):487-92. doi: 10.1111/j.1439-0531.2008.01269.x. Epub 2008 Sep 30.
Crossbred cows (n = 1073) from five locations had oestrous cycles synchronized with 100 microg of GnRH IM and insertion of controlled internal drug release device (CIDR) on Day 0 followed by 25 mg of PGF(2alpha) IM and CIDR removal on Day 7. Kamar patches were placed on all cows at CIDR removal. Cows were observed three times daily for oestrus after PGF(2alpha) administration. In the Ovsynch-CIDR group, cows detected in oestrus (n = 193) within 48 h after PGF(2alpha) were inseminated using the AM-PM rule. Among these cows, 80 received and 113 did not receive a second GnRH at 48 h after PGF(2alpha). Cows (n = 345) not detected in oestrus received a second GnRH at 48 h after PGF(2alpha) on Day 9, and fixed-time AI 16 h after the GnRH on Day 10. In the CO-Synch-CIDR group, cows detected in oestrus (n = 224) within 48 h after PGF(2alpha) were inseminated using the AM-PM rule. Among these cows, 79 received and 145 did not receive a second GnRH at 64 h after PGF(2alpha). Cows (n = 311) not detected in oestrus received a second GnRH on Day 10 at the time of AI, 64 h after PGF(2alpha). The AI pregnancy rates were not different between the Ovsynch-CIDR and CO-Synch-CIDR groups (p = 0.48). There were no differences in the AI pregnancy rates for cows inseminated at a fixed time (p = 0.26) or at detected oestrus (p = 0.79) between the treatment groups. Among cows inseminated in oestrus, there were no differences in the AI pregnancy rates between cows that received or did not receive the second GnRH (p = 0.47). In conclusion, acceptable AI pregnancy rates can be achieved with or without inclusion of oestrus detection in the Ovsynch-CIDR and CO-Synch-CIDR protocols. Among cows detected in oestrus, cows that received a second GnRH yielded similar pregnancy rates when compared with cows that did not receive the second GnRH.
来自五个地点的1073头杂交母牛，在第0天肌肉注射100微克促性腺激素释放激素（GnRH）并插入可控性内部药物释放装置（CIDR），使发情周期同步，随后在第7天肌肉注射25毫克前列腺素F2α（PGF2α）并取出CIDR。在取出CIDR时给所有母牛贴上Kamar贴片。在注射PGF2α后，每天对母牛进行三次发情观察。在Ovsynch-CIDR组中，在注射PGF2α后48小时内检测到发情的母牛（n = 193头）按照上午-下午规则进行输精。在这些母牛中，80头在注射PGF2α后48小时接受了第二次GnRH，113头未接受。在第9天，未检测到发情的母牛（n = 345头）在注射PGF2α后48小时接受第二次GnRH，并在第10天注射GnRH后16小时进行定时人工授精。在CO-Synch-CIDR组中，在注射PGF2α后48小时内检测到发情的母牛（n = 224头）按照上午-下午规则进行输精。在这些母牛中，79头在注射PGF2α后64小时接受了第二次GnRH，145头未接受。在第10天人工授精时（即注射PGF2α后64小时），未检测到发情的母牛（n = 311头）接受第二次GnRH。Ovsynch-CIDR组和CO-Synch-CIDR组的人工授精妊娠率没有差异（p = 0.48）。在各治疗组之间，定时输精的母牛（p = 0.26）或检测到发情时输精的母牛（p = 0.79）的人工授精妊娠率没有差异。在发情时输精的母牛中，接受或未接受第二次GnRH的母牛的人工授精妊娠率没有差异（p = 0.47）。总之，在Ovsynch-CIDR和CO-Synch-CIDR方案中，无论是否进行发情检测，都能获得可接受的人工授精妊娠率。在检测到发情的母牛中，接受第二次GnRH的母牛与未接受第二次GnRH的母牛相比，妊娠率相似。
