Evaporative water loss in domestic fowls and its partition in relation to ambient temperature

Abstract

Summary: The rate of evaporative water loss has been studied in domestic fowls in the ambient temperature range from 0 to 40°C.Results for whole-body evaporation were similar when obtained by the open-flow and direct-weighing methods. At low levels of absolute humidity the rate increased by 0·03 mg/(g.h.°C) from 0 to 22 °C and by 0·17 mg/(g.h.°C) from 23 to 40 °C. Wholebody evaporation decreased with rising ambient water vapour pressure by 0·7 mg/(g.h.kPa).Cutaneous water loss was greater than respiratory water loss below 21 °C; it accounted for 78% of whole-body evaporation at 0 °C, falling to 25% at 40 °C.The rates of respiratory and whole-body evaporation could both be expressed as linear functions of respiratory frequency.