发情周期和妊娠早期牦牛乳汁中孕酮含量的变化

Alternations of Milk Progesterone Contents in Wilnd Yak During Oestrous Cycle and Early Pregnancy

本试验采用放射免疫分析(RIA)方法对牦牛发情周期和妊娠早期乳汁中孕酮的含量进行了测定。在发情周期的1d和3d,礼汁中孕酮含量分别为0.4±0.08ng/ml和0.55±0.12ng/ml。而后开始显著升高,15d时达到峰值(21.37±6.58ng/ml)。随后出现下降,19,21d时降至发情之初的水平,分别为0.93±0.16ng/ml和0.42±0.07ng/ml。妊娠早期牦牛从发情配种开始到怀孕14d内乳汁中孕酮水平与发情周期牦牛乳汁中孕酮水平基本一致(P>0.05)。在怀孕的15d出现一短暂而明显的下降(15.47±2.68ng/ml)。而后含量继续升高。妊娠的19d,21d时,乳汁中孕酮含量分别为32.32±9.73ng/ml和36.45±7.56ng/ml,极显著的高于发情周期牛(P<0.001)随后妊娠早期的60d内呈持续上升的趋势。

The milk progesterone contents of wild yak during oestrous cycle and early pregnancy were radioimmunoassayed. On day 1 and day 3 in oestrous cycle, the progesterone levels were 0.04±0.08ng/ml and 0.55±0.12ng/ml respectively. After a peak value of 21.37±6.58ng/ml on day 15, the progesterone began to fall off, with a level, from 0.93±0.16ng/ml on day 19 to, 0.42±0.07ng/ml on day 21, similar to the begining of oestrous.The milk progesterone levels in early pregnant yak from insemination to day 14 of gestation were almost as high as those in oestrous cycle (P>0.05). On day 15 of gestation a sharp decrease in progesterone was observed (15.47±2.68ng/ml) and the level continued to increase short time later. On days 19 and 21 the milk progesterone was significantly greater than that of cyclic yaks (P<0.01), and continued to increase until day 60.