基于小尾寒羊母本的不同三元杂交组合对羔羊生长性能的影响研究OA

This experiment aimed to investigate the effects of using Small-tailed Han sheep as the dam line and crossing them with three different two-way cross rams(Ao-Hu,Du-Hu,and Sa-Hu)in a three-way cross system on the growth performance of their offspring lambs.The trial was conducted in Yangguang Xincun,Xijing Town,Gulang County.Local indoor-fed Small-tailed Han ewes and three types of two-way cross rams(Ao-Hu,Du-Hu,and Sa-Hu)were selected to construct the cross combinations(designated as Group A,B,and C,respectively).A control group was set up using Hu sheep×Small-tailed Han two-way crosses.All offspring lambs from the different combinations were reared under indoor feeding conditions.Their growth performance indicators were measured at 30 and 60 days of age,and at 3 and 6 months of age.The incidence rates of different diseases were recorded,and blood samples were collected at 6 months of age to determine the serum concentrations of immunoglobulin G(IgG)and immunoglobulin M(IgM).The results showed that the average body weights of lambs from the Du-Hu×Small-tailed Han combination(Group B)at 30 days,60 days,3 months,and 6 months were 5.8 kg,12.3 kg,24.3 kg,and 45.6 kg,respectively,with an average daily gain of 225.0 g/(lamb·d).The corresponding values for the Sa-Hu×Small-tailed Han combination(Group C)were 5.5 kg,11.8 kg,23.8 kg,and 44.2 kg,with an average daily gain of 218.0 g/(lamb·d).For the Ao-Hu×Small-tailed Han combination(Group A),the values were 5.3 kg,11.5 kg,23.1 kg,and 43.5 kg,with an average daily gain of 212.0 g/(lamb·d).All these values were significantly higher than those of the control group(P＜0.05).Group B lambs had the lowest incidence rates of diarrhea,respiratory diseases,and skin infections,and their serum IgG and IgM levels were extremely higher than those of the control group(P＜0.01).The study indicates that the Du-Hu×Small-tailed Han combination showed the most significant improvement effect and can provide a reference for the optimal cross combination in small-scale intensive meat sheep farming.