Dalton J C, Nadir S, Bame J H, Noftsinger M, Saacke R G
Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg 24061, USA.
J Anim Sci. 2000 Aug;78(8):2081-5. doi: 10.2527/2000.7882081x.
Thirty nonlactating Holstein cows were superovulated to determine the effect of artificial insemination time on fertilization status and embryo quality. During the luteal phase of the estrous cycle, cows were administered 38 mg FSH-P in a 4-d descending dose regimen. Luteolysis was induced with two injections of prostaglandin on the last day of FSH-P treatment. All cows were continuously monitored for behavioral estrus using the HeatWatch estrus detection system. All cows were inseminated once with one .5-mL straw (50 x 10(6) sperm) at either 0 (n = 10), 12 (n = 10), or 24 h (n = 10) after the first standing event. The elapsed time (mean +/- SD) from the first prostaglandin dose to the first standing event was 39.4 h +/- 7.7 h. The (mean +/- SD) duration of behavioral estrus was 13.2 h +/- 4.1 h. The (mean +/- SD) number of standing events was 27 +/- 17. Five hundred twenty-nine embryos and ova were recovered nonsurgically 6 d after insemination. Fertilization rates were 29 (0 h), 60 (12 h), and 81% (24 h) (P < .01). Percentages of excellent and good, fair and poor, and degenerate embryos were not different (P > .05). Percentages of embryos with accessory sperm were 5 (0 h), 8 (12 h), and 41 (24 h) and differed between the 0 and 24 h and the 12 and 24 h inseminations (P < .01). Artificial insemination of superovulated, nonlactating Holstein cattle 24 h after onset of estrus increased fertilization rate and percentage of embryos with accessory sperm compared with insemination at 0 or 12 h after onset of estrus. Embryo quality was not affected by time of insemination.
选用30头非泌乳期荷斯坦奶牛进行超数排卵，以确定人工授精时间对受精状态和胚胎质量的影响。在发情周期的黄体期，奶牛按4天递减剂量方案注射38毫克促卵泡素-垂体促卵泡素（FSH-P）。在FSH-P治疗的最后一天，通过两次注射前列腺素诱导黄体溶解。使用HeatWatch发情检测系统对所有奶牛的行为发情进行持续监测。所有奶牛在首次站立发情事件后的0小时（n = 10）、12小时（n = 10）或24小时（n = 10），用一支0.5毫升细管（含50×10⁶精子）进行一次人工授精。从首次注射前列腺素到首次站立发情事件的时间间隔（平均值±标准差）为39.4小时±7.7小时。行为发情的持续时间（平均值±标准差）为13.2小时±4.1小时。站立发情事件的次数（平均值±标准差）为27±17次。人工授精6天后，通过非手术方法回收了529枚胚胎和卵子。受精率分别为0小时组29%、12小时组60%和24小时组81%（P < 0.01）。优质、良好、中等和差以及退化胚胎的百分比无差异（P > 0.05）。有附属精子的胚胎百分比分别为0小时组5%、12小时组8%和24小时组41%，0小时与24小时以及12小时与24小时人工授精组之间存在差异（P < 0.01）。与发情开始后0小时或12小时进行人工授精相比，对超数排卵的非泌乳期荷斯坦奶牛在发情开始后24小时进行人工授精可提高受精率和有附属精子的胚胎百分比。胚胎质量不受人工授精时间的影响。
