Effects of feather cover and insulative jackets on metabolic rate of laying hens.
Two experiments were conducted to determine the influence of feather cover and newly-devised insulative jackets on the heat production in Single Comb White Leghorn laying hens at 20 C. An open-circuit calorimeter was used to measure the gaseous exchange of the birds. With ad libitum feeding, birds with clipped back and breast feathers produced 6% more heat than did normally feathered hens. This difference was removed by placing jackets on the defeathered birds. The jackets also decreased the surface temperature of the feather-clipped areas, indicating an effective insulation. When the jackets were applied to naturally poor-feathered hens, fasting heat production decreased significantly, but not to the base level of that of normally feathered hens.
D000818:Animals; D001833:Body Temperature Regulation; D001835:Body Weight; D002645:Chickens / Q000502:physiology*; D004734:Energy Metabolism; D005241:Feathers / Q000502:physiology*; D005260:Female; D010058:Oviposition; D011481:Protective Clothing