Influence of the age of chicken on the metabolisable energy values of poultry diets

Abstract

The present report concerns three experiments conducted to study abilities of birds of various ages to metabolise the energy of a practical type of diet. These abilities, expressed as the metabolisable energy values of the diet, were found to decrease rapidly during the first days after hatching. This trend in lowered ME values came to a standstill between the 7th and 9th day of age approximately and was followed by a progressive and distinct rise in the value until the 14th day. It is suggested that the initial depression may be due mainly to the decreasing of the beneficial effect of the yolk which is completely utilised during this time, while the rise could presumably be explained as due to the development of the chick's ability to digest food. Further improvement of these values to the 10th week of age can be expressed by the equation This function reached its maximum value when the birds were 50 days of age. Analyses of variance showed that both age and the individual bird had a highly significant influence on the ME value of the diet.