Physiological responses of Anglo Nubian female goats in the environmental conditions with high temperature

Abstract

The Anglo Nubian breed was investigated with the objective of evaluating in females of different ages and physiological condition, thermal status indicators of the animal in response to environmental conditions with high temperature. The animals were grouped into four ages: with more than 72 months, of 36 to 72, between 18 and 36 and gilts with 12 to 15 months. The goats were subjected to breeding season in August/September, end of gestation in December and lactation occurred in February, months in which the rectal temperature, heart rate and respiratory frequency, score and body weight, measured in the same animal when they were "not pregnant", "pregnant" and "lactation", in these months, respectively. The measurements occurred in the shade in six alternate days in each month, with readings between 14:0 and 17:0h. Randomized design has been used in 4×3 factorial experiments (ages and periods), with six repetitions. It was noted that, regardless of age, size and physiological stage, the goats using elevated respiratory rate to supplement heat dissipation, which proved to be efficient in September when the ambient temperature is high and the air humidity was low. Changes in thermal status indicator features of the animal, more sharply on rectal temperature, show that in period of the year more favorable to corporal homoeothermic must be designed to occurrence of pregnancy and lactation.