Detection and treatment of repeat breeder cows with altered epidermal growth factor expression in the uterus

该项目旨在开发重复繁殖奶牛的诊断方法和治疗方法，将子宫功能障碍作为不孕的原因之一。首先测定了子宫内膜中表皮生长因子(EGF)的分布。EGF在发情周期的第2-4天和13-14天出现两个高峰。大约70%的重复繁殖奶牛在EGF谱中表现出异常，通常缺乏这些峰值。这种异常持续在发情周期和EGF谱的正常化导致生育能力的恢复之间，表明EGF谱的异常可能是导致奶牛不孕的部分原因。然后，对异常的治疗被开发出来。当在CIDR装置的配合下给予大剂量的苯甲酸雌二醇组(EB，5 mg)时，约有70%的患者EGF恢复正常，其中70%-80%的患者在治疗后受孕。然后，在胚胎移植(ET)的受体牛中测定EGF谱，以评估子宫内膜EGF谱是否可以作为牛生育能力的指标。与EGF谱异常的奶牛相比，EGF谱正常的奶牛在ET后的妊娠率(70%比30%)更高，这表明EGF谱可以作为生育能力的指标，从而成为ET计划中受体选择的有用标记。最后，对可能影响产后EGF谱恢复的因素进行了分析。至少需要8天的黄体期才能恢复子宫内膜EGF谱中的周期性。然而，在子宫复旧前出现黄体期(&gt；11天)和重复的短黄体期(&lt；8天)似乎是在受精时增加异常EGF谱的频率的危险因素。

This project aimed to develop diagnostic method and treatment of repeat breeder cows with uterine dysfunction as a cause of infertility. First the profile of epidermal growth factor (EGF) in the endometrium was determined. EGF showed two peaks during the estrus cycles, Days 2-4 and 13-14. About 70% of repeat breeder cows showed abnormality in the EGF profile, typically lack of these peaks. This abnormality persisted between the estrous cycles and normalization of EGF profile resulted in restoration of fertility, indicating that the abnormal EGF profile may be a part of causes of infertility in dairy cattle. Then, treatment to the abnormality has been developed. When a high dose of estradiol-benzoate (EB, 5 mg) was given in combination of a CIDR device, the EGF profile was normalized in about 70% and 70-80% of them became pregnant after treatment. Then, the EGF profile was determined in recipient cattle for embryo transfer (ET) to assess if the endometrial EGF profile may serve as an indicator of fertility in cattle. Cows with a normal EGF profile showed higher pregnancy rate after ET compared with those with an abnormal EGF profile (70 vs. 30%), indicating the EGF profile can be an indicator of fertility and, thus, become a useful marker of recipient selection in ET program. Finally, factors which may affect the recovery of the EGF profile after parturition was examined. Luteal phase of at least for 8 days may be required for the recovery of cyclicity in the endometrial EGF profile. However, appearance of a luteal phase (> 11 days) before uterine involution and repeated short (< 8 days) luteal phases seemed a risk factor to increase the frequency of a abnormal EGF profile at the time of insemination.