Evaluation of the thermal comfort of goats reared in deep bedding systems in the southeast of brazil

Due to the growth in the goat production in Brazil and the increasing interest in the use of deep bedding systems, this work was aimed at the evaluation the influence of the thermal environmental comfort on the productive performance of goats in lactation reared in the deep bedding systems, by means of thermal index from data of temperature, relative humidity and air speed, beyond the radiation. The experiment was carried out at the Sector of Goat Production of the Federal University of Viçosa city, Minas Gerais State, Brazil. Forty-eight Brown Alpine and Saanen goats were used divided in three uniform groups, with average initial milk production and body weight of 2.0kg/goat and 36.0 kg. Each group of sixteen animals was lodged in three pens, in which the following treatments were applied: bed of rice hull (T1), bed of wood straw (T2) and bed of grass (T3). The thermal comfort was evaluated on the basis of the animal performance (milk production and variation of body weight). Based on these results, it was possible to conclude that, in general average, the thermal comfort of the goats, in the three treatments (beds of rice hull, wood straw and grass), based on the results of black globe temperature and humidity index (BGHTI) and radiant thermal load (RTL), was considered satisfactory, that is, these values were ranked in the acceptable threshold for animal production. The results of animal performance had also allowed to conclude the technical viability of the use of the deep bedding system in the production of goats, without significant difference between the materials used on the bed.