Intake, digestibility, physiological reactions and blood components of ovines under two temperature ranges and diets with different energy levels. II - Physiological reactions

Abstract

The objective of this work was to verify the physiological reactions (respiratory frequency, retal temperature, and pulsation) of ovines in a climatic chamber, submitted to temperatures ranging from 22 to 25°C and 32 to 35°C, relative humidity around 75%, and diets with the following four levels of metabolizable energy: normal level, recommended by the National Academy of Sciences (1975), 10% above the normal, and 10 and 20% below the normal exigencies of energy for male sheep with 30 kg of liveweight. The results obtained led to the following conclusions: 1) respiratory frequency and pulsation are directly related to environmental temperature; 2) respiratory frequency increase was insufficient to avoid increase of retal temperature in the animals; and 3) there was an interaction effect between the energy level x environmental temperature range in the retal temperature. Nevertheless, the energy levels of the rations did not influence the respiratory frequency and pulsation of the sheep.