Measuring Metabolizable Energy with Mature Hens

Metabolizable energy (ME) values of some ingredients were determined using laying hens. Diets used in these studies were composed primarily of the test ingredient plus minerals and vitamins. Mature hens, housed in separate cages, were permitted to adjust to each test diet for about 2 weeks, followed by a 3 or 4 day collection during which total feed intake and excreta output were recorded for individual birds. ME values for rice bran, wheat middlings, brewers dried grains, and alfalfa meal were found to be 2.54, 1.90, 1.84, and 1.78 kcal/g, respectively. ME for rice bran was substantially higher and for brewers dried grains lower than the reported chick values. Autoclaving rice bran (15 psi, 30 min) resulted in no significant change in its ME value. The rice bran contained 8% fat.