Effects of defeathering and insulative jackets on production by laying hens at low temperatures

Abstract
1. Exposure to a temperature of 5 °C compared with 20 °C resulted in a 20.5% increase in food consumption and an 18.8% decrease in efficiency of food utilisation with intermediate values resulting from exposure to 10 °C and 15°C. 2. Removal of feathers from the neck, back and (or) breast resulted in a 5 to 6% increase in food consumption. 3. The effects of feather removal and temperature on food consumption were additive. 4. Cloth jackets effectively insulated the back and breast areas when feathers had been removed but also resulted in increased food intake and lower efficiency.