牦牛初乳中激素含量的动态变化

Dynamic Change of Hormones Contents in the Colostrum of Yak

对麦洼牦牛(Bos.grunniens)分娩前后乳腺分泌物的生化组成进行了分析,并与常乳进行了比较。结果表明,牦牛初乳中激素含量高,分娩当天的初乳中生长激素、催乳素、胰岛素和胰岛素样生长因子含量均显著高于常乳,其中生长激素含量在泌乳第2天下降至与常乳接近,而其他激素或生长因子在初乳期前几天均显著高于常乳。另外,牦牛分娩当天和第2天乳汁中胰蛋白酶抑制剂(TI)含量显著高于常乳。

Biochemical composition of mammary gland secretions of Maiwa yak during the periparturient period was assayed and compared with that of milk. Colostrums from day 1 and day 2 of lactation had very higher level of trypsin inhibitor than milk. Significantly higher concentrations of GH, PRL, INS and IGF-Ⅰ were detected in yak colostrum from day 1 of lactation than in milk, GH concentration decreased to approximately normal level of milk after the second day of lactation, while PRL, INS, and IGF-Ⅰ maintained higher levels than milk during the first several days of lactation.