摘要
本试验旨在采用氨基酸部分扣除法研究断奶羔羊的4种必需氨基酸的限制性顺序和需要模型。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。对照组为氨基酸平衡(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赖氨酸(PD-Lys组)、蛋氨酸(PD-Met组)、苏氨酸(PD-Thr组)和色氨酸(PD-Trp组),其余氨基酸含量保持一致。预试期为10 d,正试期为60 d。于羔羊60、90和120日龄称量体重,在120日龄每组随机选取6只羔羊进行屠宰。结果表明:1)60~120日龄和90~120日龄,PD-M et组羔羊平均日增重(ADG)显著低于其他各组(P<0.05),饲料转化率(F/G)显著高于其他各组(P<0.05);120日龄时,PD-Met组宰前活重、空体重、胴体重、眼肌面积、头重、蹄重及皮毛重均显著低于PC、PD-Thr和PD-Trp组(P<0.05),但是5组间屠宰率(DP)、GR值和血液重差异不显著(P>0.05)。2)以最佳ADG和F/G为评价指标时,60~90日龄和90~120日龄氨基酸限制性顺序为Met、Lys、Thr和Trp;而以最佳DP为评价指标时,120日龄氨基酸的限制性顺序为Trp、Thr、Lys、Met。3)以最佳ADG作为评价指标时,60~90日龄和90~120日龄Lys、M et、Thr和Trp的适宜比例分别为100∶44∶44∶8和100∶42∶38∶12;以最佳F/G作为评价指标时,60~90日龄和90~120日龄Lys、M et、Thr和Trp的适宜比例分别为100∶54∶45∶7和100∶47∶39∶12;以最佳DP为评价指标时,60~120日龄Lys、M et、Thr和Trp的适宜比例为100∶34∶38∶8。总之,饲粮必需氨基酸(Lys、Met、Thr和Trp)缺乏严重影响湖羊断奶羔羊的生长性能、屠宰性能和器官指数,特别是Met影响最为明显,其次是Lys,Thr和Trp影响较弱;不同评价指标(ADG、F/G和DP)和不同生长阶段得出的Lys、M et、Thr和Trp的限制性顺序和需要模型是不同的。
This study was conducted to investigate the requirement models and sequence of 4 kinds of essential amino acids lysine（ Lys）,methionine（ Met）,threonine（ Thr） and tryptophan（ Trp） in weaned lambs by partial deduction method. One hundred male 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 Lys（ PD-Lys group）,Met（ PD-Met group）,Thr（ PD-Thr group） and Trp（ PD-Trp group） on the basis of PC group,respectively. The pretrial lasted for 10 days,and the formal trial lasted for 60 days. All the lambs were weighed at 60,90 and 120 days of age,and six lambs selected from each group were slaughtered at 120 days of age.The results showed as follows： 1） at 60 to 120 days of age and 90 to 120 days of age,average daily gain（ ADG） in PD-Met group was significantly lower than that in the other groups（ P〈0.05）,and feed to gain ratio（ F/G） in PD-Met group was significantly higher than that in the other groups（ P 〈 0.05）; at 120 days of age,PD-Met group had significantly lower live weight before slaughter,empty body weight,carcass weight,ribeye area,head weight,feet weight,and skin and wool weight compared with PC,PD-Thr and PD-Trp groups（ P〈 0. 05）,however,no significant differences of dressing percentage（ DP）,GR value and blood weight among five groups at 120 days of age were found（ P〉 0.05）. 2） Using optimal ADG and F/G as the evaluation indexes,limited amino acid sequence was Met,Lys,Thr and Trp of lambs at 60 to 90 days of age and 90 to 120 days of age; using optimal DP as the evaluation index,limited amino acid sequence was Trp,Thr,Lys and Met of lambs at 120 days of age. 3） Using optimal ADG as the evaluation index,the proper proportion of Lys,Met,Thr and Trp was 100∶44∶ 44 ∶ 8 at 60 to 90 days of age and 100 ∶ 42 ∶ 38 ∶ 12
出处
《动物营养学报》
CAS
CSCD
北大核心
2017年第1期106-117,共12页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
农业部公益性行业(农业)科研专项(201303143)
国家肉羊产业技术体系建设专项资金(CARS-39)
