Termorregulação e desempenho produtivo de codornas japonesas mantidas em diferentes temperaturas.

Abstract

The objective of this study was to evaluate the physiological variables, productive performance and thermal exchanges of Japanese quails kept in comfort and under thermal stress, using 192 quails with nine weeks of age, distributed in a completely randomized design at two temperatures (24 and 32 ºC), totaling two treatments, with 12 replicates of eight birds each, with an experimental period of 63 days, divided into 3 periods of 21 days. Respiratory rate, cloacal and surface temperature were higher at 32 ºC. Live weight, feed intake, feed conversion per egg mass, dozen eggs, yolk weight, shell, shell percentage and gizzard weight were higher at 24 ºC. Expired air temperature and heat transfer by evaporation were higher at a temperature of 32 ºC, and heat transfer by convection, radiation and total heat were higher at a temperature of 24 ºC. In the Pearson correlation with the increase in respiratory rate, feed consumption was reduced. Japanese quails in the production phase kept at temperatures of 32 ºC, showed an increase in physiological variables, reduction in final weight and egg quality, but with little influence on the performance of the birds, which used more heat transfer mechanisms in the form sensitive at the lowest temperature and latent at the highest temperature.