Nitrogen-Corrected Apparent Metabolizable Energy Value of Crude Glycerol for Laying Hens1

ABSTRACT An experiment was conducted with laying hens to determine the AMEn value of crude glycerol, a coproduct of biodiesel production. Crude glycerol (87% glycerol, 9 % water, 0.03 % methanol, 1.26 % Na, and 3,625 kcal/kg of gross energy) was obtained from a commercial biodiesel production facility (Ag Processing Inc., Sergeant Bluff, IA). A total of forty-eight 40-wk-old laying hens (Hy-Line W-36) were placed in metabolic cages (2 hens/ cage) and given free access to the experimental diets. A corn and soybean meal-based basal diet (18 % CP, 2,875 kcal/kg of AMEn, 4.51 % Ca, 0.51 % nonphytate P) was formulated with 15 % glucoseH2O and 1 % Celite. Four dietary treatments were created by substituting 0, 5, 10, or 15 % crude glycerol for glucoseH2O (3,640 kcal/kg of AMEn). After 7 d of dietary adaptation, excreta were collected twice daily for 3 d, freeze-dried, and analyzed for contents of DM, Kjeldahl N, acid-insoluble ash, and Key words: crude glycerol, biodiesel co-product, nitrogen-corrected apparent metabolizable energy, laying he