Webb R, Lamming G E, Haynes N B, Foxcroft G R
J Reprod Fertil. 1980 May;59(1):133-43. doi: 10.1530/jrf.0.0590133.
Plasma progesterone concentrations in jugular vein blood samples collected every other day after calving from 13 Friesian dairy cows indicated that ovarian cyclic activity was initiated by 16.6 +/- 1.1 (s.e.m.) days post partum, except for 1 cow which did not resume cyclic activity until Day 98 post partum. Rectal palpation of the ovaries indicated that a developing follicle was recognizable at a mean time of 15.7 +/- 2.0 days after calving. During the first oestrous cycle after parturition there was a significantly shorter period when plasma progesterone levels were elevated than during the next 2 cycles. Concentrations of progesterone, LH, FSH and prolactin were determined for 4 cows, in blood samples taken every 6 h from 2 to 36 days post partum. Tonic LH release was lower during the first 10 days than subsequently, but the lack of change in pattern for FSH suggests dissimilar control mechanisms for these hormones during this time. Three cows showed evidence of a resumption of ovarian cyclicity during the sampling period: in 2 there was an initial LH surge of a magnitude which would normally give rise to ovulation, followed 4 days later by an increase in plasma progesterone lasting only 5 and 9 days. This progesterone was considered to be of follicular origin. A second LH surge was followed by the presence of a corpus luteum.
对13头弗里生奶牛产后每隔一天采集的颈静脉血样中的血浆孕酮浓度进行检测，结果表明，除1头奶牛直到产后第98天才恢复周期性活动外，其余奶牛的卵巢周期性活动在产后16.6±1.1（标准误）天开始。通过直肠触诊卵巢发现，产后平均15.7±2.0天可识别出发育中的卵泡。在产后的第一个发情周期中，血浆孕酮水平升高的时间明显短于接下来的两个周期。对4头奶牛在产后2至36天每6小时采集的血样进行检测，测定了孕酮、促黄体生成素（LH）、促卵泡生成素（FSH）和催乳素的浓度。在产后的前10天，LH的基础释放量低于随后的时期，但FSH模式没有变化，这表明在此期间这两种激素的控制机制不同。在采样期间，有3头奶牛显示出恢复卵巢周期性活动的迹象：其中2头奶牛最初出现了通常会引发排卵的LH激增，4天后血浆孕酮增加，持续时间分别为5天和9天。这种孕酮被认为来源于卵泡。第二次LH激增后出现了黄体。
