不同阶段肉仔鸡能量需要模型的建立

Establishment of modeling of energy requirement for broiler under different stages

试验研究了0-8周龄肉仔鸡胴体与羽毛蛋白、脂肪的生长曲线及0-3、4-6和7-8周龄3个阶段每日摄入不同水平的能量及蛋白对其体蛋白、体脂肪沉积的影响,旨在确定胴体与羽毛蛋白、脂肪动态的沉积规律及日粮能量沉积为体蛋白及体脂肪的效率。试验1,包括3个饲养试验分别选取体重相近的0、21和42日龄爱拔益加（AA）肉仔鸡324只,按性别及日粮随机分为18个处理,每处理3个重复,每重复6只鸡。肉仔鸡每日限量饲喂,饲喂水平分别为正常采食量的90%、70%和50%,每日定量供给肉仔鸡高、中、低3个水平的高蛋白质基础日粮及由饲喂水平决定的定量淀粉,进而使肉仔鸡每日采食能蛋质量比（代谢能/粗蛋白）不同的9种日粮;试验2,选取体重相近的0日龄AA肉仔鸡144只,按性别不同随机分为2个处理,每处理4个重复,每重复18只鸡。试验初和试验末分别进行屠宰,以测定肉仔鸡胴体和羽毛蛋白、脂肪和干物质含量。结果显示：1）Gompertz方程能很好的拟合不同性别肉仔鸡蛋白和脂肪的生长,不同性别间蛋白和脂肪极限重量、羽毛蛋白和脂肪的生长速率差异显著（P〈0.05）,而胴体蛋白和脂肪的生长速率差异不显著（P〉0.05）。2）在0~3、4~6和7~8周龄3个阶段公、母肉仔鸡平均每kg代谢体重的能量维持需要量分别为387.53、373.21、379.09;458.73、416.60、437.14;470.44、420.04、441.42 kJ/（kg.d）。公、母肉仔鸡日粮能量沉积为体蛋白的效率分别为0.62、0.60;0.66、0.62;0.66、0.62,沉积为体脂肪的效率分别为0.59、0.64;0.75、0.80;0.77、0.81。通过上述结果可建立不同阶段肉仔鸡能量需要模型。

In order to identify the growth of protein and fat in carcass and feather,and the efficiencies of energy utilization for protein and fat deposition,the growth curve of protein and fat of broilers from 0 to 8 weeks and effects of varying energy and protein intakes on the performance,body protein and body fat of broilers at three stages were investigated.First experiment included three hundred and twenty-four 0,21,and 42 day old Arbor Acres（AA） broilers,which were randomly arranged by sex and diets into 18 treatments,where 3 replicates each treatment and 6 chicks each replication.Broilers were fed with 90%,70% and 50% restriction of ad libitum intake,separately.Each day,broilers were supplied with three allowances of high-protein basal feed and appropriate amount of starch which were determined by 3 feeding levels.Thus,9 diets with different energy to protein ratios were formed.Second experiment：one hundred and forty-four 0 day old Arbor Acres（AA） broilers were randomly arranged by sex into 2 treatments,where 4 replicates each treatment and 18 chicks each replication.At the beginning and the end of the trials,broilers were killed,and the body compositions were determined.The results showed：1） Gompertz function could describe the growth curves of the protein and fat in male and female AA chicken,and there was significant difference in the ultimate weight of protein,that of feather protein（P0.05）;and the growth rate of feather protein and that of feather fat（P0.05）,but not in the growth rate of carcass protein and that of carcass protein（P0.05） by sex;2） Average energy requirements for maintaining in male and female broilers at three stages were 387.53,373.21,379.09;458.73,416.60,437.14;470.44,420.04,441.42 kJ/（kg·d）（BW2/3）,the efficiencies of energy utilization for protein deposition in male and female broilers at three stages were 0.62,0.60;0.66,0.62;0.66,0.62,the efficiencies of energy utilization for fat deposition in male and female broilers were 0.59,0.64;0.75,0.80;0.77,0.81.Model could be constructed according to above resultto predict energy requirement for broilers.