诱导妊娠母猪白天分娩及其机理的研究

Mechanism of Parturition andSubsequent Induction of Parturition on Daytime in Sow

用氯前列烯醇对妊娠后期母猪作一次性肌注，从注射前至分娩开始，以１２小时为间隔采血，然后用放射免疫法分析血样，发现注射前血浆孕酮含量较高（１５．９５ｎｇ／ｍｌ），以后逐渐显著下降，分娩时降低到最低（５．３９ｎｇ／ｍｌ）。这说明外源性氯前列烯醇对母猪分娩前妊娠黄体有溶解作用，可导致母猪分娩提前发动。实验发现，在妊娠期１１０天、１１１天和１１２天处理母猪的白天分娩率分３１１为９０％（１８／２０）、８８．２４％（１５／１７）和７５％（１２／１６）；不同处理剂量（０．０５ｍｇ。０．１ｍｇ、０．２ｍｇ）的白天分娩率分别为８６．９６％（２０／２３）、８７．５％（１４／１６）和７８．５７％（１１／１４）；实验组的平均白天分娩率（８４．９１％，４５／５３）显著高于对照组（４５．６５％，２１／４６）；处理至分娩间隔时间平均为２４小时２４分钟。

Abstract Pregnant pigs were injected with prostaglandin's analogue ( Estrumate ) . The blood sample was collected at an interval of twelve hours from treatment to onset of farrowing. Progesterone in plasma was measured by RIA. High progesterone ( 1 5. 95ng/ml) was found in plasma before treatment ,and declined gradually after treatment ,and reached lowest concentra- tion (5. 39ng/ml) when farrowing. It indicated that the exogenous hormone could dissolve corpora letea before parturition , and result in significant declins in plasma progesterone. So parturition of sow was induced to occur ahead of shedule. More- over , results showed that parturition rate on daytime of treatment on the day 110 , 111 ,112 of gestation was 90% ( 18 /20 ) , 88. 24% (15/17) and 75% (12/16),and parturition rate on daytime of injection of 0.05mg,0.1mg and 0. 2mg per sow was 86. 96% (20/23),87. 50% (14/16) and 78. 57% (11/14),respectively. The average parturition rate on daytime of experiment group was significantly higher than that of control group ( 84 . 91% , 45/53 VS 45.65% , 21/46 ) . The mean time from treatment to onset of farrowing was 24.40 hours.