Respostas fisiológicas e hormônio cortisol como indicadores de estresse térmico em caprinos Boer em câmara climática.

Abstract

The goat in the northeast it stands out mainly by the rusticity of breeds in the region and their suitability to elevated temperature environments. The objective of this research was to assess the effects of different temperatures out in climatic chamber in physiological responses, and hormonal performance in goats of the Boer breed. The work was developed out in climatic chamber at UFCG, Campina Grande-PB. Six ¾Boer + ¼SRD goats with an average weight of 25 kg submitted to three different temperatures were used. The experiment was conducted in two stages. In the first stage three animals were subjected to three temperatures and at each temperature five days were adapted and 10 days of data collection. five days for recomposition of physiological functions between temperatures. The same procedure was adopted for the second stage. Rectal temperature, respiratory rate, heart rate and skin temperature were collected and compared four methods of estimation of Medium Superficial Temperature. Thermal gradients TS-TA, TR- TS and TR-TA were estimated and blood samples for evaluation of the hormone cortisol was collected. The design utilized was the DIC three treatments and six repetitions, the data were analyzed using SAS by applying the GLM procedures and Tukey test (T <0.05) for the significant variables. The physiological variables were directly proportional effect at ambient temperature, respiratory rate was within ranges belonging to native breeds. Heart rate ranged from 100.6 beats / min (25,7ºC) to 116.2 beats / min (33,4ºC), 15%. The skin temperature is had an increase of 24%. Gradients were affected in elevated ambient temperature, as well as the feed intake, water, weight gain and feed conversion ratio, but cortisol was not affected by high ambient temperature.