Pregnancy in dairy cows after synchronized ovulation regimens with or without presynchronization and progesterone
Pregnancy in dairy cows after synchronized ovulation regimens with or without presynchronization and progesterone
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DOI：
10.3168/jds.s0022-0302(04)73248-8
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发表时间：
2004-04-01
影响因子：
3.5
通讯作者：
Stevenson, JS
中科院分区：
文献类型：
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作者：
Ei-Zarkouny, SZ;Cartmill, JA;Stevenson, JS
两个实验检查了同步排卵（Ovsynch）后的妊娠，有或没有孕激素（P4）通过控制内部药物释放（CIDR）阴道内插入管理。在试验1中，262头泌乳奶牛在一个牛群中被分为3个处理：Ovsynch（n=91）、Ovsynch + CIDR（n=91）和对照（n=80）。Ovsynch方案包括在注射PGF（2 α）前7 d和后48 h注射GnRH。定时人工授精（TAI;产后57至77天）为第二次注射GnRH后16至20小时。Ovsynch + CIDR组的奶牛也从第一次GnRH注射开始接受CIDR（1.9 g P4）插入物7天。当使用电子发情检测系统检测到发情时，对照奶牛接受A-I。根据血清P4，44.1%的奶牛在Ovsynch前处于周期性。TAI后29 d（59.3 vs. 36.3%）和57 d（45.1 vs. 19.8%）的妊娠率以及29 - 57 d的胚胎存活率（75.9 vs. 54.5%），Ovsynch + CIDR组均高于单独使用Ovsynch组。试验2在产后59 ~ 79 d对2个牛群的630头奶牛进行6次TAI治疗。发情周期要么是预激（2次注射PGF（2 α），间隔14 d; n=318），要么是未预激（n=312）。在这些组中，Ovsynch在第二次预消化PGF（2 α）后12天开始，单独使用（n=318）或与CIDR插入物一起使用7天（1.38 g P4/插入物，n=124或1.9 g P4/插入物，n=188）。在Ovsynch之前，80%的奶牛是周期性的。在TAI后29 d，预处理增加了妊娠率（46.8%对37.5%），但在实验2中，CIDR插入物对妊娠没有影响。实验2中29 - 57 d的总胚胎存活率为57.7%。在实验1中使用CIDR插入物与Ovsynch改善了受孕和胚胎存活，但在实验2中没有，部分原因是开始时周期奶牛的比例不同。Ovsynch前预处理可提高妊娠率。
Two experiments examined pregnancy after synchronized ovulation (Ovsynch) with or without progesterone (P4) administered via controlled internal drug release (CIDR) intravaginal inserts. In experiment 1, 262 lactating cows in one herd were in 3 treatments: Ovsynch (n=91), Ovsynch + CIDR (n=91), and control (n=80). The Ovsynch protocol included injections of GnRH 7 d before and 48 h after an injection of PGF(2alpha). Timed artificial insemination (TAI; 57 to 77 d postpartum) was 16 to 20 h after the second GnRH injection. Cows in the Ovsynch + CIDR group also received a CIDR (1.9 g of P4) insert for 7 d starting at first GnRH injection. Control cows received A-I when estrus was detected using an electronic estrus detection system. Based on serum P4, 44.1% of cows were cyclic before Ovsynch. Pregnancy rates at 29 d (59.3 vs. 36.3%) and 57 d (45.1 vs. 19.8%) after TAI and embryo survival (75.9 vs. 54.5%) from 29 to 57 d were greater for Ovsynch + CIDR than for Ovsynch alone. In experiment 2, 630 cows in 2 herds received TAI at 59 to 79 d postpartum after 6 treatments. Estrous cycles were either presynchronized (2 injections of PGF(2alpha) 14 d apart; n=318) or not presynchronized (n=312). Within those groups, Ovsynch was initiated 12 d after second presynchronization PGF(2alpha) and used alone (n=318) or with CIDR inserts for 7 d (1.38 g of P4/insert, n=124 or 1.9 g of P4/insert, n=188). Before Ovsynch, 80% of cows were cyclic. Presynchronization increased pregnancy (46.8 vs. 37.5%) at 29 d after TAI, but CIDR inserts had no effect on pregnancy in experiment 2. Overall embryonic survival between 29 and 57 d in experiment 2 was 57.7%. Use of CIDR inserts with Ovsynch improved conception and embryo survival in experiment 1 but not in experiment 2, in part due to differing proportions of cyclic cows at the outset. Presynchronization before Ovsynch enhanced pregnancy rate.