FEATHER GROWTH AND FEATHER COMPOSITION OF BROILER CHICKENS

Abstract

Feather-sexed broiler chicks were reared in litter floor pens in a controlled environment building and offered mash diets meeting National Academy of Science-National Research Council specifications. Ten birds of each sex were killed at weekly intervals and individual feather weight recorded. These feathers were analyzed for crude protein and essential amino acids. From within five replicate pens of each sex, litter was removed weekly from 28 to 49 days, and molted feathers removed, cleaned and weighed. Feather weight was consistently correlated (P < 0.05) with body weight only from 5–7 wk of age. Females lost consistently more feathers than male birds, with this differential being a factor of 3.5. The methionine content of feathers decreased with age, while that of threonine, isoleucine and valine increased with age. The data are presented for use in model prediction of broiler amino acid requirements.