联合使用PGF2α和GnRH对荷斯坦奶牛进行不同的同期发情定时输精程序处理，结果表明:4次PGF2α、2次GnRH法同期发情定时输精程序处理后，奶牛子宫黏液评分和直肠检测评分分别较试验前提高了0.55分(P < 0.05)和0.45分(P < 0.05)，2次PGF2α、4次GnRH法同期发情定时输精程序处理后，奶牛子宫黏液评分和直肠检测评分分别较试验前分别提高了0.30分(P < 0.05)和0.45分(P < 0.05)。4次PGF2α、2次GnRH法同期发情定时输精程序处理和2次PGF2α、4次GnRH法同期发情定时输精程序处理后的奶牛同期发情率分别为80%、90%，第1个情期受胎率分别为65%、70%，比对照自然发情牛分别高25、30百分点。说明利用外源激素PGF2α和GnRH处理能促进奶牛卵巢和子宫复旧，达到同期发情的效果，并提高奶牛受胎率。

The experiment use different Estrus synchronization technology ways on cows selected 40 cows of postpartum 90 days or more， not estrus and infertility， were randomLy divided into test group Ⅰ， Ⅱ(n=20)， in addition， selected 20 cows of natural estrous served as control group. Use program of estrus synchronization and accurate timing of insemination for test group Ⅰ and Π. The results showed that cervical mucus score and the rectum test score were respectively increased by 0.55(P < 0.05) ， 0.45(P < 0.05) before and after the test group Ⅰ and respectively increased by 0.30(P < 0.05) ， 0.45(P < 0.05) before and after the test group Ⅱ. The rate of estrus synchronization in the test group Ⅰ and Ⅱ were 80%， 90%， respectively. Pregnancy rate in the1st estrus were 65%， 70% respectively， and they were increased by 25， 30 percentage point than that of the control， respectively. The estrus synchronization and accurate timing of insemination could promote the ovary and uterine involution， to achieve the effect of estrus synchronization， improve the pregnancy rate of dairy cow.

S663

国家自然基金项目“天然草原牧草代谢能极端变化时绵羊(Aries ovis)脂肪代谢与沉积的胁迫性响应机理研究(31460592)”、农业部公益性行业科研专项(201503134)、农业部绒毛用羊产业技术体系(CRAS39-18)、动物遗传育种与草食畜生产体系(2017GAAS30)资助。