Recent Developments in the Metabolizable Energy Feeding System for Ruminants

Equations presented predict the metabolizable energy (ME) content of feeds, and ME requirements for maintenance and production. New approaches are described for defining the maintenance requirements of penned and grazing animals, and the composition and energy of liveweight gains. The latter employs the concept of a Standard Reference Weight (SRW) to characterise the various breeds of cattle and sheep and their sex types. The SRW are also used to define the change in liveweight equivalent to unit change in condition score, and in t h e procedure for predicting feed intake which is outlined.