The Prediction of the Metabolizable Energy Content of Poultry Feedingstuffs from a Knowledge of their Chemical Composition

THE need for a rapid assay capable of measuring biologically available energy is well recognized by those concerned with the purchase of feed ingredients, the formulation of poultry diets and the quality control of mixed feeds. Conventional biological assay techniques for metabolizable energy (M.E.) require more time than is normally available when the data are to be used in the above practices. Tables of biologically derived M.E. data, while capable of serving as useful guides to ingredient purchasers and diet formulators, are not entirely satisfactory since M.E. values for samples of an ingredient may be extremely variable. For example, Sibbald and Slinger (1962) reported that M.E. values for 25 samples of wheat ranged from 1,340 to 1,800 Cal. per lb. of dry matter. Carpenter and Clegg (1956) compared the chemical compositions of 13 feed ingredients and 4 mixed diets with classical M.E. values obtained from total collection studies with…