Study on Heterosis Utilization of Dorpor Sheep with Small-tail Han Sheep

In order to study the effect of the same feed condition on growth performance and fertility of different hybrid populations,the crossbred F1,F2 and F3 of Dorpor sheep with small-tail Han sheep,Dorpor sheep and small-tail Han sheep(ram and ewe lambs)were split into several groups at random.The results indicated that the average birth weight of crossbred F1 was 3.91 kg and lower than that of the male parent(P0.05);the average daily gain from birth to weaning was 318 g and higher than that of the female parent(P0.01).In fattening period,the average daily gain of crossbred F1,F2 and F3 were 40.99%,26.13% and 22.52% respectively more than that of small-tail Han sheep(P0.01);among the three crossbreds,the daily gain was similar and showed F1F2F3.The lamb rate of crossbred F1 was 40 percent points higher than that of Dorpor sheep,and the testing result of fecundity gene(FecB) was similar to the actual lamb number.The body weight,body high,body length and chest girth of the F1~F3 multiparous ewes were all higher than those of Dorpor sheep(P0.05).The whole body conditions of crossbred F3 were superior to F1 and F2,so it was suggested that crossbred F1 should be used for fat lamb production,and crossbred F3 with FecB gene could be crossed with F2 ewes to breeding new Dorpor-Han mutton sheep.