人工诱导泌乳后血浆及乳汁中孕酮含量的动态变化

用放射免疫分析方法测定了６头激素诱导泌乳的黑白花奶牛血浆和乳汁中孕酮的含量，结果表明，诱导泌乳后乳汁中孕酮含量较高，第１ｄ时平均为７．１５±２．７９ｎｇ／ｍＬ，第２ｄ迅速升高到１６．２１±３．４５ｎｇ／ｍＬ，以后随着用药次数的增多，孕酮含量略有升高，第３ｄ及第４ｄ时分别达到１７．６６±４．１３ｎｇ／ｍＬ和１７．７７±２．３１ｎｇ／ｍＬ，随后孕酮含量逐渐下降，第５ｄ及第７ｄ时分别为１４．８４±６．２７ｎｇ／ｍＬ和１０．７６±５．５０ｎｇ／ｍＬ，第９ｄ时为１０．５０±５．０９ｎｇ／ｍＬ，此后孕酮含量急剧下降，第１５ｄ时达到３．４８±１．７５ｎｇ／ｍＬ，之后波动于１～４ｎｇ／ｍＬ之间，在整个实验期间乳汁中孕酮的浓度平均为６．３６５±２．６４９ｎｇ／ｍＬ，且呈明显的下降趋势。血浆与乳汁中孕酮含量呈明显的正相

Hormonal Induction of Lactation in Infertile Cows: Progesterone in Milk and Plasma

Concentrations of progesterone in peripheral blood plasma and milk during the first month of induced lactation in 6 Holstein cows were estimated by radioimmunoassay. Lactation was induced with estradiol 17β and progesterone treatment for 7 days.Progesterone in milk after lactation induction was rather higher, the concentration was 7 15±2 79ng/mL on Day 1 and then increased sharply to 16 21±3 45ng/mL on Day 2, 17 66±4 13ng/mL and 17 77±2 31ng/mL on days 3 and 4 respectively. There was a trend for the progesterone concentration in milk to declines as lactation progresses, the lowest values was found on day 30.