摘要
To more precisely formulate feed and predict animal performance, it is important to base both the recommendations and feed formulations on digestible rather than total amino acid contents. Most published data on the digestibility of amino acids in feed ingredients for poultry are based on excreta digestibility. Ileal digestibility is an alternative and preferred approach to estimate amino acid availability in feed ingredients. Both methodologies are described and assessed. In addition, the differences between apparent and standardised (in which corrections are made for basal endogenous losses) digestible amino acid systems are discussed. The concept of a standardised digestibility system as a mean of overcoming the limitations of apparent digestibility estimates is proposed. In this context, different methodologies for the determination of basal endogenous amino acid losses are discussed. Although each methodology suffers from some limitations and published data on endogenous losses at the ileal level in growing poultry are limited, averaged data from repeated experiments using the ‘enzymatically hydrolysed casein’ method are considered as the best measure of basal losses. Standardised ileal amino acid digestibility values of 17 feed ingredients commonly used in broiler nutrition are presented including grains (barley, corn, sorghum, triticale, wheat), grain by-products (wheat middlings, rice pollard), plant protein sources (soybean meal, canola meal, corn gluten meal, cottonseed meal, lupins, peas/beans, sunflower meal), and animal by-products (feather meal, fish meal, meat and bone meal). This comprehensive set of the ileal amino acid digestibility of feed ingredients in broiler nutrition may serve as a basis for the establishment of the system in broiler feeding and for further research.
摘要译文
为了更精确地配制饲料和预测动物性能，重要的是将推荐和饲料配方基于可消化而不是总氨基酸含量。大多数关于家禽饲料原料中氨基酸消化率的公布数据都是基于排泄物的消化率。回肠消化率是估算饲料成分中氨基酸可用性的另一种优选方法。描述和评估这两种方法。此外，讨论了表观和标准化（其中对基础内源性损失进行校正）可消化氨基酸系统之间的差异。提出了标准消化系统的概念，作为克服表观消化率估计限制的手段。在此背景下，讨论了用于确定基础内源氨基酸损失的不同方法。尽管每种方法都存在一些局限性，并且发现家禽在回肠水平上的内源性损失的公布数据是有限的，但使用“酶水解酪蛋白”方法的重复实验的平均数据被认为是基础损失的最佳量度。通常用于肉鸡营养的17种饲料原料的标准化回肠氨基酸消化率值包括谷物（大麦，玉米，高粱，黑小麦，小麦），谷物副产品（小麦中间产品，米糠），植物蛋白质来源（豆粕，双低菜粕，玉米蛋白粉，棉籽粕，羽扇豆，豌豆/豆类，向日葵粉）和动物副产品（羽毛粉，鱼粉，肉和骨粉）。这种全面的肉鸡营养中饲料成分的回肠氨基酸消化率可以作为建立肉鸡饲养系统和进一步研究的基础。
A. Lemme (a1); V. Ravindran (a2);W.L. Bryden (a3). Ileal digestibility of amino acids in feed ingredients for broilers[J]. World's Poultry Science Journal, 2004,60(4): 423-438