Efeito do ambiente térmico e uso da termografia de infravermelho em caprinos Saanen e seus mestiços com o Boer no semiárido brasileiro.

Abstract

This study was conducted to evaluate the effect of environment, with the aid of infrared thermography on thermoregulatory responses and thermal gradients of goats saanen pure and crossbred ¾ Boer + ¼ saanen in the semiarid region of Paraíba. The experiments were performed in the Research Center for the development of semi-arid (NUPEÁRIDO), of the Center for Rural Health and Technology (CSTR), Federal University of Campina Grande (UFCG) Campus of Patos-PB. Were used 18 young females, 9 saanen and 9 crossbred ¼ saanen + ¾ bôer, reared in intensive system and receiving water ad libitum and grass hay Tifton (Cynodon dactylon), with concentrate. In the first experiment it was used a completely randomized design in factorial 2x12 (two genetic groups and twelve different times) and were evaluated environmental and physiological parameters at different times: from 6 to 17 hours. In the environmental parameters it was observed that the IBGTH reached its maximum value (84.16) to 13 hours. The lowest value of IBGTH was observed at 6h. From 10 h ambient temperatures exceeded the ZCT for goats. For the TR there was statistical difference between genetic groups in times of 7, 10 and 16 hours, and the highest average found in the crossbred and times of 13,14,15 and 17 hours. For FR, the group of pure saanen and times of 14h showed the highest means. In the TS there was no effect of genetic groups and the highest means was found at 14 hours. The variation of ambient temperature influences directly the physiological responses of animals. The group saanen is less tolerant to semiarid climates than the crossbred, but maintained homeothermy with increased FR. The creation of Saanen and their crossbreeds require care for management and facilities. The second experiment utilized a completely randomized design in factorial 2x2 (two genotypes and two shifts), with 18 repetitions. The record of environmental and physiological data were performed at 08:00 and 15:00 hours. The surface temperature of each animal was obtained through a thermographic camera infrared. Subsequently the thermograms were analyzed by the Smartview software version 3.1, through which were obtained mean temperatures the regions under study (trunk and neck), considering the emissivity of 0.98. There was significant effect (P <0.05) for rectal temperature, surface temperature and thermal gradients were observed in the afternoon shift the highest averages for rectal temperature and surface temperature and in the morning, for the gradients. There was no effect of race for any of the parameters studied, except for the respiratory rate. The race saanen was less tolerant of semiarid climatic conditions than crossbred ¾ Boer + ¼ saanen, reflecting the need for more research related to the management and installations for these animals. The infrared thermography is a noninvasive technique perfectly usable and efficient to make the thermal mapping of animal and zootechnical installations.