产蛋种鸡蛋氨酸需要量的研究

本试验研究了北京红鸡父母代产蛋种鸡２１～４５周龄真可利用蛋氨酸的需要量。试验日粮为玉米—豆粕型。３个基础日粮的粗蛋白水平分别为１４．５％、１６．５％和１８．５％，蛋氨酸水平分别为０．２１％、０．２４％和０．２９％。每个基础日粮添加４个蛋氨酸水平：０、０．０５％、０．１５％和０．３０％。其它氨基酸含量都满足ＮＲＣ推荐需要量，且随粗蛋白水平升高而按比例增加。日粮含表观代谢能均为１１．２９ＭＪ／ｋｇ。共设有１２个试验处理，每个处理有８个重复，每个重复有２２只父母代产蛋母鸡。北京红鸡父母代种鸡２１～４５周龄，平均产蛋率是７６％时，在１４．５％、１６．５％和１８．５％３个粗蛋白水平下，用产蛋率指标确定的每日每只鸡总蛋氨酸的需要量分别是３１７ｍｇ、３４８ｍｇ和４１４ｍｇ；真可利用蛋氨酸的需要量分别是２８０ｍｇ、３０８ｍｇ和３６６ｍｇ；总含硫氨基酸的需要量分别是６１０ｍｇ、６２６ｍｇ和７９１ｍｇ；真可利用含硫氨基酸需要量分别是５３７ｍｇ、５７３ｍｇ和６７２ｍｇ。试验鸡的生产性能没有由于提高日粮粗蛋白水平而得到显著改善。添加蛋氨酸可以显著改善种鸡的生产性能。饲喂添加比例合适的蛋氨酸和赖氨酸、含粗蛋白１４．５％的蛋鸡日粮，可

STUDY ON THE REQUIREMENT OF METHIONINE OF BEIJINGBROWN BREEDING LAYERS

One experiment was conducted with Beijing Brown breeding layers from 21 to 45 weeks age to determine the influence of the dietary CP levels on the requirement for true digestible methionine and TSAA.0,0.05%,0.15% or 0.30% of DL-methionine were added to corn-soybean meal basal diets with 14.5%,16.5%,or 18.5% CP individually.The AME of each diet was close to 11.29MJ/kg.The levels of other amino acids of the diets met the NRC requirement sufficiently,however some increments were done as CP level increased, except the three basal diets with 14.5%,16.5%,or 18.5% CP,which contained 0.21%,0.24% and 0.29% of methionine respectively. For Beijing Brown breeding layers from 21 to 45 weeks of age with the average egg production of 76%,the true digestible methionime requirement for maximum egg production was 280mg/hd,306mg/hd,and 366mg/hd for 14.5%,16.5%CP,and 18.5%CP,respectively.Accordingly,the true digestible TSAA was 537mg/hd,573mg/hd,and 672mg/hd. The Breeding layers'performance can be improved by addition of methionine in their ration.There was no significant difference between the performance of layers fed a diet with 14.5% CP level and that of those fed diets with 16.5% or 18.5% CP levels if appropriate methionine and lysine were added.