简介:

Kristjan Bregendahl在Degussa的09年1月份的AMINOnews上发表了最新的蛋鸡氨基酸模型的综述，在下搜索到了这篇08年的文章以飨网友，有兴趣的也可以和Degussa联系索要一下这份资料。结合起来看效果更好的。个人认为这个实验对蛋鸡理想氨基酸模型目前来看更系统更有应用价值。 Ideal Amino Acid Profile for 28-to-34-Week-Old Laying Hens Kristjan Bregendahl,1 assistant professor; Stacey Roberts, graduate research assistant; Brian Kerr, research leader, USDA/ARS; Dirk Hoehler, director of technical services, Evonik Degusssa Corporation Summary and Implications The ideal amino acid (AA) profile employs the concept that, whereas absolute AA requirements change due to genetic or environmental factors, the ratios among them are only slightly affected. Thus, once the ideal AA profile has been determined, the requirement for a single AA (i.e., lysine) can be determined experimentally for a given field situation and the requirements for all the other AA calculated from the ideal ratios. Seven separate experiments were conducted with laying hens to determine the ideal ratio of arginine, isoleucine, methionine, methionine+cystine, threonine, tryptophan, and valine relative to lysine for maximal egg mass. The assays were conducted simultaneously using the same basal diet to which crystalline AA were added to create the graded level of the respective assay AA and to ensure that the assayed AA was first limiting. Hens were fed the assay diets from 26 to 34 weeks of age, with the first 2 weeks considered a depletion period. Egg production was recorded daily and egg weight was determined weekly on eggs collected over 48 hours; egg mass was calculated as egg production × egg weight. The requirement for each AA was determined using the broken-line regression method. Consumption of arginine did not affect egg mass, thus an ideal arginine:lysine ratio could not be determined. The ideal AA ratio for maximum egg mass for 28-to-34-week-old laying hens was isoleucine 79%, methionine 47%, methionine+cystine 94%, threonine 77%, tryptophan 22%, and valine 93% on a true digestible basis relative to lysine. Introduction Amino acid requirements for laying hens are published by the National Research Council.2 However, the experiments upon which these requirements are based are dated and do not account for the genetic progress of laying hens in the last 12 or more years. Amino acid requirements have been reported since the publication of the National Research Council requirements. However, these experiments have been conducted for 1 AA at a time, performed under different experimental conditions and with different basal diets, genetic lines of hens, feed consumption rates, dietary energy contents, ambient temperature, cage space, and ages of laying hens, all of which influence the AA requirements. Because multiple factors affect AA requirements, requirements determined under experimental conditions may not be applicable under field conditions. The solution to obtaining reliable AA requirements is therefore not to determine the AA requirements, but rather to determine the ideal AA profile for laying hens. The ideal AA profile employs the concept that, while AA requirements change drastically due to genetic or environmental factors, the ratio among them is only slightly affected. Thus, once the ideal AA profile has been determined, the requirement for a single AA (e.g., lysine) can be determined experimentally for a given field situation and the requirement for all the other AA calculated. Such an approach has been adopted with success by the swine industry and is finding use in the broiler industry as well.