Características adaptativas de caprinos nativos em ambiente termoneutro e de estresse consumindo água salina.

Abstract

The objective of this work was to evaluate the biochemical and hormonal variables of the Moxotó and Canindé goats breeds, submitted to two different temperatures controlled in climatic chambers, consuming water with different levels of salinity. Twelve whole males were used, 6 Moxotó and 6 Canindé with mean age of 5.0±0.6 months and mean weight of 20.0±2.3 kg. These animals were housed in metabolic cages within the climatic chamber, equipped with drinking fountains and feeders. The climatic chambers were 19.71 m² in area and had a height of 2.38 meters. The animals were submitted to two controlled temperatures, T1 = 26 ± 0.6 ºC (thermal comfort zone - ZCT) and T2 = 32 ± 1.2 ºC (above ZCT), consuming water with three different levels of salinity ( 1.0, 6.0 and 12.0 dS m-1). Blood and hormonal biochemical variables did not show a significant effect (P>0.05) among races with the exception of the gamma glutamyltransferase. As also with the exception of glucose and urea, the other blood variables did not show significant effect (P>0.05) for water salinity. Glucose, cholesterol, protein, albumin, globulin, AST and hormones (T4, T3 and cortisol) had a significant effect (P<0.05) for temperature. The hormonal variables had a significant effect (P<0.05) for hours. The biochemical and hormonal variables undergo changes as a function of temperature and diurnal variation so that metabolism is reduced in thermal stress and accelerated at low temperature.