Bayril Tahir, Yilmaz Orhan
Faculty of Veterinary Medicine, Department of Animal Husbandry, Dicle University, 21280, Diyarbakir, Turkey.
Trop Anim Health Prod. 2013 Feb;45(2):411-6. doi: 10.1007/s11250-012-0231-0. Epub 2012 Jul 22.
The objective of this study was to determine the effect of timing of artificial insemination on pregnancy rates, calving rates, abortion rates, twinning rates, and calf gender ratio after synchronization of ovulation with Ovsynch protocol in Holstein dairy cows. The ovulation of 219 lactating Holstein dairy cows was synchronized using the Ovsynch protocol. Therefore, cows received an injection of GnRH followed by an injection of prostaglandin F(2α) 7 days later and a second treatment with GnRH 2 days later. Cows were artificially inseminated at 0, 12, or 24 h after the second injection of GnRH. Reproductive performance did not differ between cows inseminated at 0 h (n = 82), 12 h (n = 66), or 24 h (n = 71) after the last injection of GnRH (pregnancy rate: 0 h 48 %, 12 h 47 %, 24 h 52 %; abortion rate: 0 h 5 %, 12 h 0 %, 24 h 11 %; calving rate: 0 h 43 %, 12 h 47 %, 24 h 41 %; twinning rate: 0 h 2 %, 12 h 0 %, 24 h 0 %; calf gender ratio (F/M): 0 h 61:39 %, 12 h 48:52 %, 24 h 39:61 %; P > 0.05). Pregnancy rates for cows inseminated in postpartum times of 50-75, 76-100, and >100 days within the first and ≥ 3 parities were statistically similar (P > 0.05), but pregnancy rates for cows inseminated at different postpartum times of 50-75, 76-100, and >100 days within the second parity were different (P < 0.01). In general, pregnancy rates of cows inseminated at different postpartum times (P < 0.01) and parities (P < 0.001) differed. The findings of the current study showed that rates of pregnancy, abortion, calving, and twinning of Holstein dairy cows subjected to artificial insemination at different times after synchronization were similar. These results also indicate that the timing of artificial insemination after synchronization did not influence calf gender ratio. Furthermore, pregnancy rates of Holstein dairy cows inseminated after synchronization were significantly influenced by postpartum time and parity number.
本研究的目的是确定在荷斯坦奶牛中使用Ovsynch方案同步排卵后，人工授精时间对妊娠率、产犊率、流产率、双胎率和犊牛性别比例的影响。使用Ovsynch方案对219头泌乳期荷斯坦奶牛的排卵进行同步处理。具体做法是，给奶牛注射促性腺激素释放激素（GnRH），7天后注射前列腺素F（2α），再过2天进行第二次GnRH处理。在第二次注射GnRH后的0、12或24小时对奶牛进行人工授精。在最后一次注射GnRH后0小时（n = 82）、12小时（n = 66）或24小时（n = 71）进行人工授精的奶牛，其繁殖性能没有差异（妊娠率：0小时48%，12小时47%，24小时52%；流产率：0小时5%，12小时0%，24小时11%；产犊率：0小时43%，12小时47%，24小时41%；双胎率：0小时2%，12小时0%，24小时0%；犊牛性别比例（雌/雄）：0小时61:39%，12小时48:52%，24小时39:61%；P > 0.05）。在第一胎及≥3胎产后50 - 75天、76 - 100天和>100天进行人工授精的奶牛，其妊娠率在统计学上相似（P > 0.05），但在第二胎产后50 - 75天、76 - 100天和>100天不同时间进行人工授精的奶牛，其妊娠率不同（P < 0.01）。总体而言，在不同产后时间（P < 0.01）和胎次（P < 0.001）进行人工授精的奶牛，其妊娠率存在差异。本研究结果表明，同步后在不同时间进行人工授精的荷斯坦奶牛，其妊娠、流产、产犊和双胎率相似。这些结果还表明，同步后人工授精的时间不影响犊牛性别比例。此外，同步后进行人工授精的荷斯坦奶牛的妊娠率受产后时间和胎次的显著影响。
