Fat supplementation in animal production--ruminants

The effect of adding fat to the diet of the ruminant is a very complex subject. For animals with a low production potential, the role of fat is probably limited but, as the potential output is increased, energy intake becomes a more important limiting factor and the use of more fat may then be justified. If this is so, certain problems require solution. These include the effects on food intake and its metabolizability and the ME value to be assigned to the fat itself. In dairy cows, the best way to feed fat, either early in lactation or throughout, needs to be assessed together with any effects in later lactations. Finally, the best form of fat to use and the method of incorporating it into the diet also needs to be investigated.