初胎牛围产期某些代谢激素的分泌特点

Secretion Characteristics of Some Metabolic Hormones during Perinatal Period in Holstein Cows

12头初胎荷斯坦牛,经颈静脉采取预产期前10天、3天和产后3天、10天、17天血样,测定血浆中TSH、T_3、T_4和胰岛素的含量。结果表明:从预产期前10天开始到产后第17天,①T_3的水平呈平稳稍升高的趋势;②T_4的水平以预产期前10天的为最高,随后均显著下降(P<0.01);③TSH在产后的第3天和17天均显著高于预产期前10天的水平(P<0.05);④预产期前10天胰岛素含量显著高于其它时间的水平(P<0.01)。以上结果提示:初胎荷斯坦牛围产期TSH、T_3、T_4和胰岛素的含量均发生改变,以促进营养物质的转化和加强蛋白质的合成,适应机体泌乳的生理变化。

Twelve first-fetus Holstein cows were used in this study to evaluate the changes of some metabolic hormones in plasma during parturition period. The blood samples were collected via the superior vena cava and analyzed by radioimmunoasssay.① From the 10 day of expected date of childbirth to day 17 after parturition, T3 contents were increased significantly (P<0.01), except day 10 after parturition. ② During the experiment period, T4 contents in day 10 of expected date of childbirth were higher than those of the other days (P<0.01).③Compared with day 10 expected date of parturition, TSH contents of day 3 and day 17 after parturition were decreased by 26.11%(P<0.05) and 52.65% (P<0.01), respectively. ④ All the insulin contents were lower than that of day10 expected date of parturition (P<0.01). These results indicate that the TSH,T3,T4 and insulin levels were changed to prompt the nutriment transform and protein synthesize, so that to adapt the physiological changes of the perinatal and lactation in Holstein cows.