小尾寒羊高繁殖力和常年发情内分泌机理的研究

本研究对5只小尾寒羊成年母羊以及相同条件下的5只细毛羊成年母羊用导管法采血,用放射免疫分析法测定血浆中FSH和LH浓度.试情公羊爬跨法鉴定结果表明,小尾寒羊具有显著的非季节性发情特性.小尾寒羊各月份、4个季节和全年的血浆FSH和LH浓度均极显著高于(P＜0.0001)低繁殖力和季节性发情的细毛羊.小尾寒羊发情期血浆FSH和LH的基础浓度、峰值、谷值、排卵前峰值均显著高于(P＜0.05～P＜0.0001)细毛羊的.发情期间小尾寒羊和细毛羊FSH分泌呈现2个明显的峰,第一个峰与排卵前LH峰并存,第二个FSH峰出现在发情后1d.小尾寒羊FSH二次峰均值极显著高于(P＜0.01)细毛羊的.本研究结果提示FSH和LH基因可作为小尾寒羊高繁殖力的候选基因来加以研究.

STUDY ON ENDOCRINE BASIS OF PROLIFICACYAND NON-SEASONAL ESTRUS IN SMALL TAIL HAN SHEEP

The peripheral blood samples of 5 adult Small Tail Han ewes and 5 adult fine wool ewes were collected.The plasma FSH and LH concentrations were measured by radioimmunoassay.Small Tail Han sheep had significant characteristics of non seasonal estrus.The plasma FSH and LH concentrations in Small Tail Han sheep were significantly higher(P<0 0001)than those in fine wool sheep during twelve months,four seasons and the whole year.The basic concentration,peak value,minimum,preovulatory peak value of plasma FSH and LH during estrous period in Small Tail Han sheep were all significantly higher(P<0 05 or P<0 01 or P<0 001 or P<0 0001)than those in fine wool sheep.There were two separate FSH surges observed during estrous period in two breeds.The first FSH surge coincided with the preovulatory LH surge and the second FSH surge occurred on day 1 of the cycle.The average peak value of the second FSH surge in Small Tail Han sheep was significantly higher(P<0 01)than that in fine wool sheep.These results suggested that both FSH and LH genes could be considered as candidate genes for the prolificacy in Small Tail Han sheep.