Thermal comfort index, physiological variables and performance of quails fed with protein reduction

ABSTRACT The objective of this study was to determine the effects of environment and electrolyte balance on environmental, physiological and productive indices of Japanese quails. For the experiment, 288 quails were distributed in a randomized block design with six treatments and six replicates of eight birds per experimental unit. The treatments consisted of one basal feed with 20.0% of crude protein (CP) and the others with a reduction of 3.0% CP to achieve six electrolyte balance levels (166.54; 153.47; 139.63; 139.63; 117.13 and 166.49). As to the environment, there was an increase in air temperature and temperature-humidity index at the hottest hours of the day, causing discomfort to the birds, which increased respiratory rate, but with the maintenance of homeothermy. Differences were observed in feed consumption, water consumption, production, weight of eggs and mass of eggs, due to the electrolyte levels in the feed. For feed conversion, both per mass and per dozen of eggs, there was no statistical difference. The electrolyte balance and environmental indices at the hottest hours of the day did not affect quail production