30～38周龄产蛋鸡理想氨基酸模式的研究

本试验旨在通过4个剂量-反应试验,研究30～38周龄产蛋鸡对赖氨酸(Lys)、蛋氨酸(Met)、色氨酸(Trp)和苏氨酸(Thr)4种必需氨基酸(AA)的需要量及其比例.每个试验均采用360只海兰灰产蛋鸡,设5个处理,分别采食5个AA梯度水平的试验饲粮,每个处理6个重复,每个重复12只鸡.采用蛋公鸡回肠食糜法测定饲料原料的标准回肠可消化(SID)值.试验预试期14 d,正试期56 d.结果表明:海兰灰产蛋鸡的产蛋率、蛋重、日产蛋量和料蛋比与SIDLys、SID Met、SID Trp和SID Thr的摄入水平均有较好的折线回归关系；以日产蛋量为自变量(x),AA摄入水平为依变量(Y)分别建立的回归方程为:YSID Lys=51.60-0.041 6(682.5-x),R2=0.96;YsID Met=51.43-0.085(314.1-x),R2 =0.95;YSID Trp =51.17-0.155 4(163.0-x),R2=0.97；YsID Thr=52.85-0.057 6(499.5-x),R2=0.93.在饲粮粗蛋白质12.8％的条件下,以日产蛋量为参照指标确定的30 ～ 38周龄产蛋鸡的SID Lys、SID Met、SID Trp和SID Thr需要量分别为684、313、171和506 mg/(只·d).以日产蛋量为指标建立的30～38周龄产蛋鸡理想SID AA模式为:Lys:Met:Trp:Thr=100∶46∶24∶73.

Ideal Amino Acid Pattern for Laying Hens Aged Thirty to Thirty-Eight Weeks

Four separate experiments were conducted to study the requirements and ideal ratio of lysine(Lys),methionine(Met),tryptophan(Trp) and threonine(Thr) for laying hens aged 30 to 38 weeks.Three hundred and sixty Hy-Line laying hens were randomly divided into five dietary treatments with six replicates per treatment and 12 laying hens per replicate.The standardized ileal amino acid digestibility of ingredients was determined using the ileal assay with adult roosters.Crystalline amino acids were added into a basal diet to yield 5 graded inclusions of the assayed amino acid.Hens were fed the trial diets for 10 weeks,with the first 2 weeks considered a preliminary trial period.The results showed that the responses to the intake level of standardized ileal digestible(SID) Lys,SID Met,SID Trp and SID Thr fitted well one-slope broken-lines and the regression equations based on daily egg production were as follows: YSID Lys=51.60-0.041 6(682.5-x),R2=0.96;YSID Met=51.43-0.085(314.1-x),R2=0.95;YSID Trp=51.17-0.155 4(163.0-x),R2=0.97;YSID Thr=52.85-0.057 6(499.5-x),R2=0.93.The results show that the SID amino acid requirements for Hy-Line laying hens aged 30 to 38 weeks for maximum Daily egg production were 684 mg/(h·d) of Lys,313 mg/(h·d) of Met,171 mg/(h·d) of Trp and 506 mg/(h·d) of Thr,respectively.The ideal amino acid ratio for Hy-Line laying hens aged 30 to 38 weeks for maximum daily egg production was Lys∶Met∶ Trp∶ Thr=100∶ 46∶ 24∶ 73.