2001 feed composition guide

摘要

Typical composition of commonly used feeds for sheep and cattle. Nutrition research spanning more than 100 years has defined the nutrients required by animals. Using the feed composition information in the accompanying table, diets can be formulatedfrom feedstuffs and ingredients to meet these requirements with the expectation that animals will not only remain healthy but will also be productive and efficient. The goal of feedstuff analysis is to predict the productive response of animals when theyare fed diets of a given composition. Feedstuffs are not of constant composition. Unlike chemicals that are "chemically pure" and therefore have a constant composition, feeds vary in their composition for many reasons. Actual analysis should be obtainedand used whenever possible. Often, however, it is impossible to determine actual composition, or there is insufficient time to obtain such analysis, and therefore tabulated data are the next best source of information.