Development of bovine estrous synchronization program adapted for small scale Japanese livestock industry

为了恢复分娩后的生殖功能，开发了激素治疗以恢复卵巢功能，并对未怀孕的奶牛进行了早期妊娠诊断和再同步化。日本黑牛(n=50)在分娩后30天进行生殖器官的新鲜检查，有黄体(CL)的奶牛用前列腺素F2ARuFa(PGF2a)处理，没有黄体(CL)的奶牛用GnRH处理。7天后，经阴道放置孕酮装置(PRID、CIDR)7~9天，拔除时注入前列腺素F2a。注射雌二醇-17β(E_2)24小时或促性腺激素释放激素(GnRH)48小时，16~20小时后行定时人工授精(AI)。人工授精后第10天检测CL同步依从性，第28天进行超声早孕试验。在荷斯坦奶牛(n=40)中，类似的…结果表明，鲜检时卵巢中存在CL，日本黑牛为35-40%，荷斯坦黑牛为45-70%，不同奶牛的卵巢CL含量不同。拉取PRID或CIDR后，97.5%进行了定时AI，10d后确认CL为90%~95%，无品种差异。日本黑牛早孕受胎率为35%~60%，荷斯坦黑牛为27%~53%，GnRH处理优于E2处理。非孕母牛受胎率分别为发情间期46%、发情后期15%、发情前期22%、卵巢囊肿14%、间情期3%。对非妊娠奶牛进行再同步化，其中患有CL的奶牛注射PGF2a，而没有CL或卵巢囊肿的奶牛注射AS CIDR。再同步化后1周内观察发情情况，40%受孕进行人工授精。受胎率与对照牛相当，但再同步化母牛在初次人工授精后第31.2天进行第二次人工授精，而对照组为56天。因此，早期恢复生殖道和卵巢功能是提高母牛妊娠率的关键。发情或发情同步检测和定时人工智能是现代畜牧业所必需的。人工授精后，对非妊娠奶牛进行再同步化和人工授精，超声早孕试验是重要的检测手段。较少

In order to recover the reproductive function from parturition, hormonal treatment was developed for resumption of ovarian function, and early pregnancy diagnosis together with resynchronization for non-pregnant cows was conducted. These synchronization methods were adapted for the small scale Japanese livestock industry.In Japanese black cows (n=50), fresh check of reproductive organs was conducted on day 30 after parturition, and cows with corpus luteum (CL) was treated with Prostaglandin F2 arufa (PGF2a) and cows without CL was treated with GnRH. 7 days later, progesterone devices (PRID, CIDR) was inserted for vagina for 7-9 days and PGF2a was injected when they were pulled. Estradiol - 17 beta (E2) on 24 h or GnRH on 48h was injected and timed artificial insemination (AI) was performed 16-20 h later. On day 10 after AI, CL was detected for synchronization compliance and early pregnancy test by ultrasonography was conducted on day 28 after AI. In Holstein cows (n=40), similar protoc … More ol was performed, but initial treatment was conducted 2 weeks later followed with progesterone insertion seven days later.In the results, CL was existed in the ovary at fresh check for 35-40% in Japanese black cows and 45-70% in Holsteins, and these were varied depend on the cow group. Timed AI was performed for 97.5% after pull of PRID or CIDR, CL was confirmed 10 days later for 90-95%, and there was no breed difference. Conception rate at early pregnancy test was varied for 35-60% in Japanese black cows and 27-53% in Holsteins, and GnRH treatment was superior to E2 treatment.Ovarian findings in non-pregnant cows at pregnancy test were diestrus 46%, metestrus 15%, proestrus 22%, ovarian cysts 14% and anestrus 3%. Resynchronization was performed for non-pregnant cows in which PGF2a was injected for cows with CL while as CIDR was inserted for cows without CL or ovarian cysts. Estrus was observed within a week after resynchronization, and AI was performed with 40% conception. Conception rate was comparable to control cows, but second AI was performed on day 31.2 after initial AI in resynchronized cows compared to day 56 in controls.In conclusion, early resumption of reproductive tract and ovarian function were keys for the improvement of pregnancy rate in cow herd. Detection of estrus or estrous synchronization and timed AI were necessary for the modern livestock industry. After AI, early pregnancy test by ultrasonography was important for detection of non-pregnant cows, which were subjected for resynchronization and AI. Less