【摘要】 对雌禽性成熟阶段（开产前）内分泌变化的研究很少,有关鸭的尤其少见。本实验选用距开产约半个月的北京鸭73只,个体笼养并有产蛋记录。用放射免疫法测定了雌二醇、孕酮和甲状腺激素（三碘甲腺原氨酸即T₃、甲状腺素即T₄）,用比色法测定了总脂的含量。 发现血浆雌二醇开产前13～8天有明显上升的趋势。15～13天平均值是53.4Pg/ml。开产前12天上升,于开产前8天达到峰值108.9Pg/ml,开产前6天开始下降,到产前降至基础值。 血浆孕酮开产前15天各天之间没有显著差异,平均值为1.4ng/ml。 血脂含量开产前半个月各天之间有显著差异,开产前15～6天之间波动不大,平均值为866mg/100ml。从开产前第5天开始上升,至开产前1～2天含量达到峰值2532mg/100ml。 血浆T₃在开产前15天各天之间也有显著差异,且与血脂含量呈极显著的负相关。T₃在开产前15～10天之间含量变化不大,平均值为:1.74ng/ml,从开产前第9～5天下降,于第4～0天降至最低值,平均值为0.75ng/ml。 血浆T₄含量在开产前半个月各天之间波动不显著,与血浆总脂含量呈负相关,平均值为8.3ng/ml。但在个体测定中,接近产蛋时T₄含量均有明显下降的趋势。更多还原

【Abstract】 Little has been known concerning the hormonal status before laying of the female birds, especially in the duck.Seventy three Peking Ducks, 140 days old and about half a month before laying, were used in this experiment. They were housed in individual cage throught the period of investigation and the laying record was kept individually. Three to four ml. of blood from each duck was taken on every fifth or sixth day. The plasma was prepared immediately and stored at - 15℃ pending analysis.Radioimmunoassay was used to determine the concentration of the plasma estradiol,progesterone, triiodothyronine and thyroxine. The plasma total lipid was determined by colorimetric analysis.The plasma estradiol increased remarkably from day 13 to day 8 preceding the onset of laying (p<0.01 ). The average value of estradiol was 53.4 pg/ml on days 15 to 13 and elevated from day 12 up to a maximum value ( 108.9 pg/ml ) on day 8 . The peak value began to decline on day 6 and fall to the basic value on day 2 , just before the laying of the first egg.Progesterone concentration showed small fluctuation during this period. Its average value was 1.4 ng/ml.The plasma total lipid value was significantly different ( P<0.01 ) from each day for half a month before laying. No significant difference (P>0.05)was observed in plasma total lipid from day 15 to day 6 before laying. The average value was 866 mg/100ml. The total lipid started to increase from day 5 and reached the peak ( 2532 mg/100ml ) on days 2 to 1 before laying.The daily plasma T3 concentration was also fluctuated significantly(P<0.05)for half a month before laying. A high negative correlationexisted between plasma T3 and total lipid ( P<0.01 ) . No significant daily difference in plasma T3 concentration was noted from day 15 to day 10 before laying with an average value of 1.74 ng/ml. However, it started to decrease from day 9 to day 5 and attained its lowest value(0.75 ng/ml ) from day 4 to day 0 before laying.As a whole, the difference of daily T4 concentration was insignificant statistically(P>0.05).But there was a clear trend of decline in most of the individual cases ( P<0.05 ). Its average value was 8.3 ng/ml.更多还原