Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands.
Anim Reprod Sci. 2011 Jun;126(1-2):101-7. doi: 10.1016/j.anireprosci.2011.04.015. Epub 2011 Apr 29.
This study assessed pulsatile release of LH during altrenogest treatment after weaning in primiparous sows and related this to follicle development, estrus and ovulation rate. Weaned sows (n=10) received altrenogest 20mg/day from D-1 to D13 (weaning=D0) at 0800 h. On D13, blood samples were collected every 12 min from 1000 until 1900 h (1st sampling period) and from 2300 h until 0800 h (2nd sampling period). During the 1st sampling period, LH concentrations remained low and no LH pulses were detected in 8/10 sows. During the 2nd sampling period, average and basal LH concentrations (P<0.04) and frequency of pulses (P<0.0001) were higher than during the 1st sampling period. Sows with short vs. long intervals to estrus (<5 days vs. ≥5 days) had higher basal and average LH concentrations during the 2nd sampling period (P≤0.004) and showed more follicular growth during treatment (P=0.007), generating larger follicles at D14 (P=0.005). Sows with high ovulation rate (≥25) displayed more LH pulses in total than sows with low (<25) ovulation rates (P=0.03). In conclusion, this study showed that altrenogest efficiently prevented LH pulsatility during the first bleeding period and that low frequency/high amplitude LH pulses were generally present during the second bleeding period. This variability in LH release in between two altrenogest administrations (24h) may explain why follicular growth progresses to 5mm during altrenogest treatments. LH pulsatility was related to length of the follicular phase and ovulation rate, which signifies its relevance.
本研究评估了初产母猪断奶后烯丙孕素治疗期间 LH 的脉冲释放，并将其与卵泡发育、发情和排卵率相关联。断奶母猪（n=10）于 D-1 至 D13（断奶=D0）每天接受烯丙孕素 20mg，时间为 0800 小时。在 D13 时，从 1000 时到 1900 时（第 1 个采样期）和从 2300 时到 0800 时（第 2 个采样期），每 12 分钟采集一次血液样本。在第 1 个采样期，8/10 头母猪的 LH 浓度保持较低水平，未检测到 LH 脉冲。在第 2 个采样期，平均和基础 LH 浓度（P<0.04）和脉冲频率（P<0.0001）均高于第 1 个采样期。发情间隔较短（<5 天）与较长（≥5 天）的母猪在第 2 个采样期的基础和平均 LH 浓度较高（P≤0.004），且在治疗期间表现出更多的卵泡生长（P=0.007），在 D14 时产生更大的卵泡（P=0.005）。排卵率较高（≥25）的母猪总的 LH 脉冲数多于排卵率较低（<25）的母猪（P=0.03）。总之，本研究表明，烯丙孕素在第一次出血期间有效阻止了 LH 脉冲，并且在第二次出血期间通常存在低频率/高幅度的 LH 脉冲。在两次烯丙孕素给药（24 小时）之间 LH 释放的这种可变性可能解释了为什么卵泡生长在烯丙孕素治疗期间进展到 5mm。LH 脉冲与卵泡期长度和排卵率相关，这表明其相关性。
