Effects of sex, age and food intake upon metabolisable energy values in broiler chickens

Abstract

1. Nitrogen‐corrected apparent metabolisable energy (AMEn) values of 2 diets with different energy: protein ratio were estimated in an experiment with 8 groups of female and 8 of male chickens in 15 sequential 3‐day balance periods from the 12th to the 56th d of age. 2. The effect of sex on AMEn values was not significant. 3. The effect of age was highly significant. AMEn values of the mixture with the narrower energy: protein ratio increased with age. The dependence of AMEn of the diet with the wider energy: protein ratio on age was parabolic, AMEn values increasing only until the 37th day of life. 4. Under conditions of ad libitum feeding, AMEn of the mixture with the wider energy: protein ratio given to female chickens decreased significantly with increasing food intake.