本试验旨在研究开食料必需氨基酸(赖氨酸、蛋氨酸、苏氨酸和色氨酸)部分扣除对断奶湖羊羔羊屠宰性能和不同部位氨基酸含量的影响.选取50日龄断奶湖羊公羊100只随机分为5组,每组4个重复,每个重复5只羊.对照(PC)组饲喂氨基酸平衡的开食料,4个试验组开食料在PC组的基础上分别扣除30%赖氨酸、蛋氨酸、苏氨酸和色氨酸,分别作为PD-Lys、PD-Met、PD-Thr和PD-Trp组,其余氨基酸含量保持一致.预试期为11 d,正试期为60 d.在120日龄每组随机选取6只羔羊进行屠宰.结果表明:1)PD-Lys和PD-Met组与PC组相比空体重、皮毛重、胴体重、蹄重显著降低(P<0.05);2)PD-Met组胴体粗蛋白质含量显著低于PC和PD-Trp组(P<0.05),PC、PD-Lys 和 PD-Met 组皮毛粗脂肪含量显著低于 PD-Thr 和 PD-Trp 组(P<0.05),PC组胴体粗脂肪含量显著低于其他各组(P<0.05),PD-Met组头蹄水分含量显著低于PC和PD-Lys组(P<0.05);3)PD-Met组头蹄、皮毛的必需氨基酸和非必需氨基酸及胴体必需氨基酸含量显著低于PC组(P<0.05).综合以上结果得到,61~120日龄断奶湖羊赖氨酸、蛋氨酸、苏氨酸和色氨酸4种必需氨基酸理想模式如下:胴体为100:35:44:13,皮毛为100:21:129: 11,头蹄为100:34:70:7.
This experiment was conducted to research the effects of essential amino acids[lysine(Lys), me-thionine(Met), threonine(Thr)and tryptophan(Trp)]partial deduction in starter on slaughter performance and amino acid contents in different parts of Hu lambs. One hundred Hu lambs weaned at 50 days of age were randomly divided into five groups and each group had four replicates with five lambs per replicate. Control group was fed a starter with balanced amino acid(PC group),while 4 experimental groups were fed the starter deducting 30% Lys,Met,Thr and Trp based on control group,respectively,which were recorded as PD-Lys, PD-Met, PD-Thr and PD-Trp groups, respectively. The pretest lasted for 11 days, and the formal trial period lasted for 60 days. Six lambs selected from each group were slaughtered at 120 days of age. The results showed as follows:1)empty body weight, skin and wool peel weight, carcass weight and feet weight in PD-Lys and PD-Met groups were significantly lower than those in PC group(P<0.05). 2)Carcass crude protein content in PD-Met group was significantly lower than that in PC and PD-Trp groups(P<0.05), wool ether extract con-tent in PC, PD-Lys and PD-Met groups was significantly lower than that in PD-Thr and PD-Trp groups(P<0.05), PC group has the lowest carcass ether extract content compared with the other groups(P<0.05), and moisture of head and feet in PD-Met group was significantly lower than that in PC and PD-Lys groups(P<0.05). 3)Essential amino acids and non-essential amino acids contents in head and feet, skin and wool, as while as carcass essential amino acids content in PD-Met group were significantly higher than those in PC group (P<0.05). In conclusion, the ideal essential amino acid models of Lys, Met, Thr and Trp of weaned Hu lambs from 60 to 120 days of age are as follows:carcass,100:21:129:11;skin and wool,100:34:70:7;and head and feet,100:35:44:13.