Period of dominance of the ovulatory follicle influences embryo quality in lactating dairy cows
Period of dominance of the ovulatory follicle influences embryo quality in lactating dairy cows
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DOI：
10.1530/rep-08-0242
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发表时间：
2009-05-01
期刊：
影响因子：
3.8
通讯作者：
Santos, Jose E. P.
中科院分区：
文献类型：
--
作者：
Cerri, Ronaldo L. A.;Rutigliano, Heloisa M.;Santos, Jose E. P.
排卵卵泡的优势长度和在发情前期暴露于雌二醇（OE 2）可以影响生育力。泌乳奶牛的发情周期预先同步，并接受四种同步处理之一。发情检测（OD）处理组奶牛在发情周期第6天接受GnRH，7天后接受PGF（2 α），并在检测到发情时进行授精。剩余奶牛从发情周期的第3天（OVS 3）或第6天（OVS 6和OVS 6 E）开始接受Ovsynch（OVS）方案（第0天GnRH，第7天PGF（2 α），第9天GnRH，12小时后定时人工授精（Al））。OVS 6 E治疗组的奶牛在Al前36 h注射0.5 mg环戊丙酸雌二醇。通过超声检查卵巢，并采集血样用于孕酮和OE 2浓度。Al后6天冲洗子宫，并评价回收的胚胎-卵母细胞。A1时排卵卵泡直径在各处理间差异显著（P < 0.01），其中OVS 3组最大，优势卵泡长度延长（P < 0.01）。在发情前期，OD和OVS 6 E奶牛的发情率均有所增加（P <7. 05）。与其他处理相比，OVS 3奶牛（P < 0.01）回收的胚胎和胚胎-卵母细胞的存活胚胎比例较小，OVS 3奶牛的胚胎也具有较少的卵裂球（P < 0.01），并且往往具有较低的活卵裂球比例（P = 0.09）。延长卵泡优势期不影响受精率，但降低了受精率（P
Length of dominance of the ovulatory follicle and exposure to oestradiol (OE2) during proestrus can affect fertility. Lactating cows had their oestrous cycle pre-synchronized and were subjected to one of the four synchronization treatments. Cows in the oestrus detection (OD) treatment received GnRH on day 6 of the oestrous cycle, PGF(2 alpha), 7 days later, and were inseminated at detected oestrus. The remaining cows were subjected to the Ovsynch (OVS) protocol (day 0 GnRH, day 7 PGF(2 alpha), day 9 GnRH, and timed artificial insemination (Al) 12 h later) starting on day 3 (OVS3) or day 6 (OVS6 and OVS6E) of the oestrous cycle. Cows in the OVS6E treatment received an injection of 0.5 mg oestradiol cypionate 36 h before Al. Ovaries were examined by ultrasonography and blood was sampled for progesterone and OE2 concentrations. Uteri were flushed 6 days after Al and recovered embryos-oocytes evaluated. Diameter of the ovulatory follicle at Al differed (P < 0.01) among treatments, and it was the largest for OVS3 cows, which also had extended (P < 0.01) length of follicular dominance. During proestrus, OD and OVS6E cows had increased (P 7. Proportions of viable embryos in relation to embryos and embryos-oocytes recovered were smaller for OVS3 cows (P < 0.01) than the other treatments, and embryos from OVS3 cows also had fewer (P < 0.01) blastomeres and tended (P = 0.09) to have a lower proportion of live blastomeres. Extending the period of follicle dominance did not alter fertilization but reduced (P