1. Agricultural Research Council (1980) The Nutrient Requirements of Ruminant Livestock. Commonwealth Agricultural Bureaux, Slough.
2. Agricultural Research Council (1981) The Nutrient Requirements of Pigs. Commonwealth Bureaux, Slough.
3. Heat loss from sheep;Alexander,1974
4. Cell bioenergetics and energy metabolism;Armstrong,1969
5. Maintenance requirements: implications for its use in feed evaluation systems;Armstrong,1984