Effects of age and sex of broilers on metalic efficiency of dietary energy utilization

Abstract

160 day old Indian River chicks (80 males and 80 females) were fed diets containing high (3,200 kcal ME/kg) and low (2,900 kcal ME/kg) levels of energy and 3 levels of protein (23%: 1-21 days; 21% 22-42 days; 19%: 43-56 days). The classical (MEc) and corrected (MEn) metabolizable energy values were determined according to age and sex. There were no significant differences between the values of MEc and MEn found in the first 3 weeks of age. However, these data were significantly lower than those obtained in the last 5 weeks of age. Chicks metabolized significantly more gross energy from high energy diet than a low energy diet, during both the first 4 weeks and the last 2 weeks of age. Data indicated that females utilized the dietary energy between 5 and 8 weeks more efficiently than males.