Evaluation of timed insemination using a gonadotropin-releasing hormone agonist in lactating dairy cows
Evaluation of timed insemination using a gonadotropin-releasing hormone agonist in lactating dairy cows
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DOI：
10.3168/jds.s0022-0302(96)76496-2
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发表时间：
1996-08-01
影响因子：
3.5
通讯作者：
Thatcher, WW
中科院分区：
文献类型：
--
作者：
Burke, JM;DelaSota, RL;Thatcher, WW
一项实验比较了定时人工智能和人工智能在观察到的发情期的有效性。泌乳奶牛在产后3d注射PGF（2 α）30 +/-，3d注射GnRH激动剂65 +/-，7 d后注射PGF（2 α）;对照母牛（n = 128）在检测到的发情期授精，定时人工授精组（n = 171）在注射PGF（2 α）后48 h再次注射GnRH激动剂，16 h后进行人工授精。对照组7 d内未授精的母牛用GnRH激动剂处理，7 d后注射PGF（2 α）。对照组受胎率为30.5%，定时人工授精组受胎率为29.0%，对照组受胎率为41.5%，定时人工授精组受胎率为26.5%。产后120 d受孕的奶牛开放日数为对照组83.6 d，定时AI组79.2 d。给药与月份的相互作用表明，对于定时AI组的奶牛，妊娠率和受孕率以及受孕奶牛的开放天数在各个月之间更加一致。产后120天的总妊娠率未检测到差异（对照组与定时Al组）（58.8 +/- 4.7%与56.2 +/- 4.4%）。第一次同期妊娠的受孕率和妊娠率受产后65 d的身体状况和血浆孕酮浓度的影响。定时人工授精是一种有效的生殖管理方法。
An experiment compared the effectiveness of a timed AI and an AI at observed estrus. Lactating dairy cows were injected with PGF(2 alpha) at 30 +/- a range of 3 d postpartum, with a GnRH agonist at 65 +/- a range of 3 d, and with PGF(2 alpha) 7 d later; control cows (n = 128) were inseminated at detected estrus, but cows in the timed AI group (n = 171) received a second injection of GnRH agonist 48 h after the injection of PGF(2 alpha) and were inseminated 16 h later. Control cows that were not inseminated within 7 d were resynchronized with GnRH agonist, followed 7 d later with an injection of PGF(2 alpha). Pregnancy rate was 30.5% for control cows and 29.0% for cows in the timed AI group, and conception rate was 41.5% for control cows and 26.5% for cows in the timed Al group. Days open for cows that conceived by 120 d postpartum was 83.6 d for control cows and 79.2 d for cows in the timed AI group. Treatment by month interactions indicated that pregnancy and conception rates and days open for cows that conceived were more consistent across months for cows in the timed AI group. Differences (control vs. timed Al) were not detected for overall pregnancy rate by 120 d postpartum (58.8 +/- 4.7% vs. 56.2 +/- 4.4%). Conception and pregnancy rates at first synchronization were influenced positively by body condition and plasma concentrations of progesterone at 65 d postpartum. Timed AI was an effective alternative for reproductive management.