Comportamento ingestivo de ovinos Santa Inês consumindo água com diferentes níveis de salinidade mantidos em ambiente controlado.

Abstract

This study aimed to evaluate physiological parameters, thermal gradients and adaptability of Santa Inês sheep at different temperatures and consuming different levels of salinity in the water. The study was conducted in a climate chamber using nine sheep, males, submitted to two climatic conditions, 25 ° C - within the thermal comfort zone (ZCT) and 32 ° C - above the ZCT, with relative humidity (RH) average by 60% and three salinity levels 2, 4 and 8 dS / m conductivity. Every day the climate chamber was sealed at 08:00 am, opened at 16:00 hours, totaling 8 hours and 16 hours of stress kept in an open environment. During the trial period we collected data on air temperature (TA), relative humidity (RH) and determination of the ITU, in addition to the physiological parameters respiratory rate (RR), heart rate (HR), rectal temperature (RT) and skin temperature (ST), thermal gradients between the surface and rectal temperatures (TR-SW) and between the superficial and ambient temperatures (ST-TA), to determine the animal's adaptability to temperatures studied; Beyond these were conducted heat tolerance coefficient Iberia or Rhoad (CTC) and the Benezra test (CA1 and CA2). The experimental design was a factorial (2 x 3 x 3), the main portion the two temperatures and the subplot with three water levels and 3 repetitions. Salinity levels caused no changes in animal behavior parameters and physiological parameters. There was statistical difference with increasing temperature for ST, FC and FR, and the TR remained within normal limits. ITU indicated at 32 ° C gave weather hazard, the temperature was 25 ° C which provided greater thermal comfort for the animals.