It is not possible to recommend precise feeding strategies that will apply to all sheep flocks in agricultural areas. Similarly, it is not possible to recommend levels of supplementary feeding that will apply under all conditions, since farms and paddocks within farms differ and should be judged independently. This Farmnote outlines some important characteristics of feeds, types of feed supplements and how they should be costed, and gives some generalizations that apply to the five objectives listed above. Metabolizable energy is calculated from feed digestibility and estimates the total energy available to the animal. The energy values of roughages are low and variable, while those of grains are much higher and less variable.
Energy is the main deficiency of stock in poor grazing conditions.
This also includes any non-protein nitrogen components such as urea. In the rumen, microbial fermentation of forages low in protein is reduced. This leads to incomplete digestion of the available energy and to low intakes. This is particularly important with dry grass residues in summer. Feeds low in protein can limit wool growth.