Laboratory of Theriogenology, Department of Veterinary Medicine, Faculty of Agriculture, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan.
J Dairy Sci. 2011 Jan;94(1):116-27. doi: 10.3168/jds.2010-3213.
A database of milk progesterone profiles consisting 497 lactations in 3 dairy herds from northern and western regions of Japan was used to identify the characteristics and associated risk factors for prolonged luteal phase (PLP) and its effects on subsequent reproductive performance in high-producing Holstein cows. Milk samples were collected twice weekly and progesterone concentrations in whole milk were determined by ELISA. Herds were visited monthly and examined by vaginoscopy and transrectal palpation. Resumption of ovarian cyclicity within 35 d postpartum followed by regular cycles was considered normal. Prolonged luteal phase was defined when progesterone concentrations were ≥5 ng/mL for ≥20 d of duration in any cycle postpartum. Delay of first ovulation to 35 to 60 d (delayed first ovulation type I), >60 d (delayed first ovulation type II), a luteal phase of <14 d except in the first cycle (short luteal phase), and the absence of luteal activity >14 d between 2 cycles (cessation of cyclicity) were the other categories of abnormal ovarian resumptions considered. The overall incidence of PLP in the 3 herds was 11.9% and a significantly higher proportion of PLP was observed in the first cycle postpartum compared with the second and third cycles. Approximately 83% of the PLP were 20 to 28 d in duration, and maximum progesterone concentration was significantly higher when PLP lasted >35 d compared with PLP of 20 to 35 d in duration. Higher parity, commencement of luteal activity≤28 d postpartum, and postpartum complications significantly increased the occurrence of PLP within 90 d postpartum. Cows with PLP showed reduced conception rate to first artificial insemination (AI) and reduced pregnancy proportions within 100, 150, and 210 d postpartum. Based on survival analysis, PLP was associated with a 56% reduction in relative pregnancy rate and a 36% reduction in AI submission rate. Cows that experienced PLP had a longer interval from calving to first AI (74 d) and from calving to pregnancy (141 d) than cows without PLP (53 and 80 d), respectively. In conclusion, 11.9% of lactations had PLP, of which approximately two-thirds were seen in the first cycle postpartum. Most of the PLP were 20 to 28 d in duration. Higher parity, postpartum complications, and early commencement of luteal activity postpartum increased the risk for PLP. Occurrence of PLP adversely affected fertility by reducing pregnancy proportions and extending calving to conception interval.
一个由来自日本北部和西部地区的 3 个奶牛场的 497 次泌乳组成的牛奶孕酮谱数据库被用来确定延长黄体期（PLP）的特征和相关风险因素，以及其对高产荷斯坦奶牛随后生殖性能的影响。每周采集两次奶样，通过 ELISA 测定全乳中的孕酮浓度。每月访问一次奶牛场，通过阴道镜检查和直肠触诊进行检查。产后 35 天内恢复卵巢周期性并随后出现正常周期被认为是正常的。当产后任何一个周期中孕酮浓度≥5ng/mL且持续时间≥20 天时，定义为延长黄体期。排卵延迟至 35-60 天（排卵延迟 I 型）、>60 天（排卵延迟 II 型）、黄体期<14 天（除第一个周期外）、两个周期之间黄体活动持续时间>14 天（周期性停止）是其他异常卵巢恢复的分类。这 3 个牛场的 PLP 总发生率为 11.9%，与第二和第三个周期相比，产后第一个周期 PLP 的比例明显更高。大约 83%的 PLP 持续 20-28 天，当 PLP 持续时间>35 天时，最大孕酮浓度明显高于持续 20-35 天的 PLP。更高的胎次、产后黄体活动开始≤28 天和产后并发症显著增加了产后 90 天内 PLP 的发生。发生 PLP 的奶牛首次人工授精（AI）的受胎率降低，产后 100、150 和 210 天的妊娠比例降低。基于生存分析，PLP 与相对妊娠率降低 56%和 AI 提交率降低 36%相关。经历 PLP 的奶牛从产犊到首次 AI（74 天）和从产犊到妊娠（141 天）的间隔时间分别长于未经历 PLP 的奶牛（53 和 80 天）。总之，11.9%的泌乳期存在 PLP，其中大约三分之二发生在产后第一个周期。大多数 PLP 持续 20-28 天。更高的胎次、产后并发症和产后黄体活动的早期开始增加了 PLP 的风险。PLP 的发生通过降低妊娠比例和延长产犊至妊娠间隔时间，对奶牛的繁殖力产生了不利影响。
