Study on variations of five reproductive hormones of small tail nail sheep during lactating period | 泌乳期小尾寒羊5种生殖激素的变化规律研究

Chinese. 研究泌乳期小尾寒羊血清中5种生殖激素（FSH、LH、PRL、P4、E2）质量浓度的变化规律。分别在春、秋季于小尾寒羊产羔0~60 d内，每隔5 d采血1次，共采13次，颈静脉采集试验羊全血10 mL，离心后收集血清，再用放射免疫分析法（RIA）测定血清中FSH、LH、PRL、P4和E2的质量浓度。春、秋季小尾寒羊母羊在产后泌乳初期（0~5 d），血清中FSH、LH、E2和P4的质量浓度均处于较低水平。春、秋季小尾寒羊产后第10 天，外周血中FSH质量浓度开始上升，第40天分别达到各自平均水平，春季为（29.61±12.40） ng/mL，秋季为（32.60±12.59） ng/mL；LH质量浓度在产后5 d开始上升；PRL浓度在产后前5 d保持较高水平，之后缓慢下降直到试验结束（60 d）；E2质量浓度总体均呈波动上升趋势，在45 d时均出现峰值，春季为（73.84±59.46） pg/mL，秋季为（65.33±35.09） pg/mL，之后维持在较高水平直到试验结束；P4质量浓度总体均呈现出波动上升的变化趋势，并分别在45 和55 d出现最高峰(（0.55±0.31）和 (0.70±0.43) ng/mL）。泌乳母羊产后血清中P4质量浓度变化在个体间的差异较大，产后60 d内每个试验羊均有卵巢活动，最早出现卵巢活动的时间为产后第10 天。小尾寒羊在产后40 d内生殖器官的各项功能均已得到基本恢复，此时对小尾寒羊进行诱导发情可以得到较好的效果。

English. The regularity of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), progesterone (P4) and estradiol (E2) concentrations in the serum of small tail nail sheep during lactating period was studied. The day that ewes yeaned was considered as the day that the experiment began. Then whole blood samples were collected through jugular vein every 5 days until the 60th day after parturition. The blood was collected 13 times in all. Whole blood samples were determined as FSH, LH, PRL, P4, E2 concentrations by radiommunoas-say (RIA). FSH, P4, E2 concentrations in the serum of small tail nail sheep were all at a low level during 5 days after parturition in spring and autumn. FSH concentrations began to increase on the 10th day after parturition, and reached their average values ((29.61±12.40) ng/mL and (32.60±12.59) ng/mL) on the 40th day after parturition. LH concentrations in the serum of small tail nail sheep in the spring and autumn began to increase in waves after 5 days. The ranges of PRL concentration in the serum were the highest on the day of parturition, then declined gradually during the test. E2 concentrations increased, and the peak existed on the 45th day average ((73.84±59.46) pg/mL and (65.33±35.09) pg/mL). Then E2 concentrations in the serum maintained at a high level. P4 concentrations in the serum of small tail nail sheep maintained at a low level within 10 to 60 days after parturition in spring and autumn. The peaks existed on the 45th (0.55±0.31) ng/mL and 55th day (0.70±0.43) ng/mL, respectively. P4 concentration variations in the serum of lactating ewes after parturition showed individual diversities obviously after comparing P4 concentrations in the serum of each lactating ewe. All of lactating ewes’ ovaries showed activities within 60 days, of which the earliest activities existed on the 10th day after parturition. It is clear that reproductive organ function of small tail nail sheep has recovered by 40th day after parturition and it is feasible to induce oestrus at this time.