Metabolic rate and thyroid activity of hens in relation to the state of feathering.
Heat production, rectal temperature and thyroid activity were determined in NH X Lg hens that were 40 and 80% defeathered. Within individual groups there was a significant increase in heat production only in hens that were 80% defeathered. In comparison with the control group, defeathered chickens had higher metabolic rates during each examined period. During the third week of the experiment there was a temporary drop in the rectal temperature of the experimental birds. After nine weeks chicken with the greatest degree of defeathering had the highest thyroid weight and the highest levels of thyroxin in the blood plasma.
D000818:Animals; D001833:Body Temperature Regulation; D001835:Body Weight; D002645:Chickens / Q000378:metabolism*; D005241:Feathers / Q000502:physiology*; D005260:Female; D009929:Organ Size; D013961:Thyroid Gland / Q000378:metabolism*; D013974:Thyroxine / Q000097:blood
D013974:Thyroxine