初产母猪断乳至发情的激素水平

LH, E 2 and P 4 Levels from Weaning to Postweaning Oestrus in Primparous Sows

３头瘦肉型杂交一代初产母猪，于产后２８～３０ｄ实行分段断乳。从断乳前１ｄ至断乳后发情日，多次采血，测定其血浆中黄体生成素（ＬＨ）、雌二醇（Ｅ２）、孕酮（Ｐ４）的水平。结果表明，（１）３种激素断乳前均处于低水平；（２）断乳后Ｅ２和ＬＨ先后增高，而Ｐ４直到发情后才升高，ＬＨ水平升高是预示母猪断乳后将要发情的一个指征；（３）泌乳期失重较多的母猪，其Ｅ２、ＬＨ水平的升高时间推迟，进而发情也推迟。

The fractionated weaning has been conducted in three primparous crossbred sows (F1) from 28 day to 30 day of lactation. One day prior to weaning until postweaning oestrus day, the blood samples were taken from auricular vein for measurement of the concentrations of LH, 17β E 2 and progesterone (P 4). The results showed that: ①LH, E 2, P 4 kept a low level during the lactation; ②E 2, LH got increasing after weaning, while P 4 did since the postweaning oestrus, indicating that the high levels of LH might be an anticipator of postweaning oestrus; ③The increase of the E 2, LH levels and the postweaning oestrus appeared to be of delay when the sow had lost heavily its body weight during lactation.