Food Intake and Utilization of Lysine-Deficient Protein by the Chick in Relation to the Digestible Energy Concentration of the Diet

Abstract

Semipurified diets containing 15% sesame protein and various levels of lysine were fed ad libitum to two-week old chicks for a period of 18 days. The substitution of 12% or more of cellu flour (wood-pulp cellulose) for an equal weight of glucose resulted in improved growth with all of the diets deficient in lysine. The improved growth was most readily attributed to the increased feed and lysine intake in response to the decrease in the digestible energy concentration of the diets caused by the substitution of cellu flour for glucose. Feed intake varied inversely with the digestible energy concentration of the diet, and energy intake appeared related to energy needs. At adequate dietary levels of lysine, the introduction of 12% of cellu flour had little effect on growth, but at all lysine levels, the presence of 12% of cellu flour reduced the estimated metabolizable feed energy required per unit of weight gain.