Increasing exogenous progesterone during synchronization of estrus decreases endogenous 17 beta-estradiol and increases conception in cows.
Increasing exogenous progesterone during synchronization of estrus decreases endogenous 17 beta-estradiol and increases conception in cows.
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在发情同步期间增加外源孕酮会降低内源 17 β-雌二醇并增加奶牛的受孕率。
DOI：
10.1095/biolreprod49.2.214
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发表时间：
1993
影响因子：
3.6
通讯作者：
J. Kinder
中科院分区：
文献类型：
--
作者：
M. Wehrman;M. Roberson;A. Cupp;F. Kojima;T. Stumpf;L. A. Werth;M. Wolfe;R. Kittok;J. Kinder
本研究旨在探讨人工授精前不同剂量外源性孕酮(P4)对母牛17β-雌二醇(E_2)水平和受胎率的影响。小母牛(n=100)和奶牛(n=100)接受P4释放阴道内装置(PRID)，以产生两种不同的循环浓度的P4。所有动物在繁殖季节开始(第0天)前10天(第10天)接受单一PRID。在接受低剂量P4(1个PRID，目标浓度为2-3 ng/ml血浆)的动物中，原始PRID保持10天。在接受较大剂量P4(2个PRID，目标浓度为5-8 ng/ml血浆)的动物中，在第9天插入额外的PRID。为了维持2-PRID组的P4浓度，分别在-5天和-4天用新的PRID替换-10天和-9天插入的PRID。在第9天和第3天给所有动物注射前列腺素F2α(25 Mg)，以消除P4的内源性来源。去除PRID后，动物在观察到行为发情迹象后12h进行人工授精。观察到了小母牛和奶牛循环中P4浓度的逐日处理交互作用(p<；0.0001)。在治疗的第8天，接受2次PRID的动物比接受1次PRID的动物有更高的P4浓度(p<；0.001)。在接受1次PRID的奶牛中，从第10天(6.8+/-1.0pg/ml)到第二天(16.7+/-1.4pg/ml)，E2浓度增加了2.4倍。
The objectives of this study were to determine the effects of dose of exogenous progesterone (P4) prior to artificial insemination on concentrations of 17 beta-estradiol (E2) and on conception rates in bovine females. Heifers (n = 100) and cows (n = 100) received P4-releasing intravaginal devices (PRIDs) to produce two different circulating concentrations of P4. All animals received a single PRID 10 days before (Day-10) the start of the breeding season (Day 0). In animals that received the low dose of P4 (1 PRID, target concentration of 2-3 ng/ml of plasma), the original PRID remained in place for 10 days. In animals that received the larger dose of P4 (2 PRIDs, target concentration of 5-8 ng/ml of plasma), an additional PRID was inserted on Day -9. To maintain concentrations of P4 in the 2-PRID group, the PRIDs inserted on Days -10 and -9 were replaced with new PRIDs on Days -5 and -4, respectively. Prostaglandin F2 alpha (25 mg) was administered to all animals on Days -9 and -3 to remove the endogenous source of P4. Following PRID removal, animals were artificially inseminated 12 h after signs of behavioral estrus were observed. A treatment-by-day interaction (p < 0.0001) was observed for concentrations of P4 in circulation of both heifers and cows. Animals that received 2 PRIDs had greater (p < 0.001) concentrations of P4 by Day-8 of treatment than animals that received 1 PRID. In cows that received 1 PRID, concentrations of E2 increased 2.4-fold from Day-10 (6.8 +/- 1.0 pg/ml) to Day-2 (16.7 +/- 1.4 pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)