Housing and selenium influences on feathering in broilers

A majority of the broilers produced around the world are sexed on the basis of rapid-feathering females or slow-feathering males, which is facilitated by the presence of the sex-linked, auto-sexing, slow-feathering K gene in males. Recent advances in materials have allowed development of a caging system that is a viable alternative to the traditional floor-rearing regimen. In this study, a comparison was made between the traditional floor- and cage-rearing environments and their influence on feathering of auto-sexing, sex-linked male and female broilers fed at 0.2 mg/kg of feed either NaSe or an organic selenium yeast (OR). Feed conversion ratios, BW, and mortality were not affected by Se source. Feather tracts on the back, breast, thigh, wing, neck, and wing were scored subjectively based on feather size and skin surface covered. Feather scores ranged from 0 (no feathering) to 5 (best feathering) for each tract. The OR induced more rapid whole body feathering in, the slow-feathering males as well as in the normal-feathering females. The influence of OR was evident from 21 through 42 d of age. Females had a faster feathering rate than did males. Females approached full feathering at 35 d of age, but males lagged behind females even at 142 d. Feathering of broilers in the conventional house was slightly faster than the feathering of broilers in the cage house. The mechanism for improved feathering rate in normal-feathering females and slow-feathering males given OR has not been determined.