Physiological responses of crossbred boer goats finished in native pasture in the semiarid

In this study, it was evaluated physiological responses of crossbred Boer goats finished in native pasture. The experiment was carried out at experimental farm of Federal University of Campina Grande (UFCG), Patos, Paraiba, Brazil. Were used Twenty-four goats with 120 days of age. The animals were randomly assigned to according to a completely randomized design, being evaluated two shifts (morning and afternoon) with six replications (goats). It were recorded environmental parameters ambient temperature (AT), relative humidity (RH) and wind velocity and determined humidity and black globe temperature index (HGTI) in the shade and in the sun and radiant thermal load(RTL) in the shade and in the sun. The physiologic parameters were evaluated according to the methodology described by Santos et al. (2006) with measurements of rectal temperature (RT), respiratory rate (RR) and skin temperature (ST). There was significant effect of shift of the environmental parameters with (HGTI) in the sun of 93.10 and radiant thermal load (RTL) in the sun of 819.07 W.m-2 . The period of the day affected the physiological responses RT, RR and ST with averages values of 39.38 °C, 56.85 mov/min and 34.30 °C, respectively. There was significant effect in relation to the time of day on the physiologic parameters of goats Boer crossbreeds. The thermal gradient between rectal temperatures and superficial and between the superficial temperature and environmental is an indicator of heat stress for goats studied.