国产LRH—A_3提高河北细毛羊受胎率最佳剂量试验

Study on the Optimal Dose of Chinese LRH-A_3 for Rairing Pregnancy Rate of Hebei Finl Wool Sheep

在河北细毛羊配种季节，根据发情羊只数，随机分成３组，即试验１组：在输精的同时每只羊肌注ＬＲＨ－Ａ３４０μｇ；试验２组注射８０μｇ；对照组只输精不注射．然后比较其情期受胎率，第２年根据上一年的试验结果，在同一时期、同一羊群内，调整ＬＲＨ－Ａ３剂量．即试验３组，每只羊注射５０μｇ．试验回组注射１００μｇ；时照组只输精不注射．其它方法均相同，以筛选ＬＲＨ－Ａ３的最佳剂量，试验结果表明：ＬＲＨ－Ａ３的最佳剂量为５０μｇ，情期受胎率为９３．５％（２９／３１），较对照组７３．５％（２５／３４）提高２００个百分点，差异显著（Ｐ＜０．０５）．有效剂量为４０～８０μｇ，比对照组的情期受胎率提高４．４～２０．０个百分点．结果表明，在配种的同时，给细毛羊注射适宜剂量的ＬＲＨ－Ａ３方法简单适用，提高受胎率效果显著，可作为提高养羊生产经济效益的一项技术措施进行推广．

The present study was undertaken to And optimal cross combination of Hebei fine woos sheep val commercial cross with surnames of Charolai and Border Leicester being male parents.The results showed that the mean body weight(MBW)of Charolai fivemonth-old cross-breed lanmbs and Border Leicester five-month-old cross-breed ram lambs reached or approached 25kg,and that of seven-month-old ones was over 30kg,being significantly higher(P<0.01)than that of Hebei fine wool ewe lambs which was 25.64kg. The coparative experiment of small amount feeding(SAF)and Grazing(G)revealed significantdifferences(p<0.01)between every testing groups in which the MBW of Hebei fine wool sheep G group lambs was the lowest,both that of SAF group and that of Gvgroup of Charolai cross-breed lambs was he highest(39.25 and 35.59kg).With better Pasture in 1994,the MBW of Charolai grazig cross-breed lambs eached 39.89kg,while their mean carcass weight(MCW)reached 17.gkg over the world mean standard(16kg)of marketing sheep of all,developed countries in 1992.At last a conclustlon was put for ward that Charolai was the optimum paternity for Hebei fine wool sheep commercial cross breeding.