| Grazing and rangeland development for livestock production |
|Management of rangelands and other grazing lands of the tropics and subtropics for support of livestock production. Technical Series Bulletin No. 23|
|VI. Estimating Feed Requirements of Ruminant Livestock in Tropical and Sub-Tropical Regions.|
Nutrient content (and feed value) of forage plants is determined by the content of digestible nutrients, by the protein component, and by the adequacy in supplies of essential mineral elements. Since mineral supplements may be provided separately from forages, it is convenient to use two principal factors in estimating feed value; total digestible nutrients (T.D.N.), and protein content.
In calculating available feed supplies for grazing livestock the following averages may be utilized in converting the yearly production of plant herbage into animal support.
Mature tropical grasses may be assumed to contain about 50% T.D.N., and 4.0 to 6.0 % crude protein.
Perennial range legumes may be assumed to contain about 60 % T.D.N., and 12 to 15% crude protein.
Browse plants generally are more nutritious than grasses, but less so than forage legumes. me forage supply on rangelands tends to be deficient In protein content in the long dry seasons that are typical of rangelands; as well as being chronically inadequate in total amount of edible forage.