Sensible and latent heat flow of Japanese quails kept in different thermal environments

Abstract

The aim of this study was to estimate the heat flux through sensitive mechanisms and respiratory evaporation of Japanese quails kept in thermoneutral and warm environments, using simple environmental and physiological measures. 192 nine-week-old quails were used, distributed in a completely randomized design at two temperatures (T1 = 24 °C and T2 = 32 °C), with 12 replicates of eight birds each, with an experimental period of 63 days, divided into three 21-day periods. Physiological measurements of respiratory rate (RR), cloacal temperature (TC) and body surface temperature (TS) were measured twice a week. The behavior of the energy balance in the climatic chambers was obtained using the total thermal energy exchanges per unit surface area of ​​the birds, derived from the sum of sensible (radiation and convection) and latent heat exchanges. Respiratory rate (P<.0001), surface temperature (P<.0001) and cloacal temperature (P=0.0047) were higher in the 32 °C environment. The expired air temperature (P<.0001) and heat loss by respiratory evaporation (P<.0001) showed higher values ​​when the quails were in an environment of 32 °C, while the heat losses by convection (P<.0001) and radiation (P<.0001) were higher in a thermal comfort environment. In Japanese quails kept in a controlled environment, sensible heat dissipation by convection is the main way to eliminate excess thermal energy, when the air temperature is up to 32 ºC.