Respostas fisiológicas e desempenho de caprinos canindé e moxotó suplementados com concentrado energético no semiárido equatorial

Abstract

Goat farming in the semiarid region of the Northeast is important for the local economy, with breeds adapted to the dry and hot climate. However, to optimize the productive performance of these goats, management practices, nutritional supplementation and strategies to reduce heat stress are necessary. The objective of this study was to evaluate the physiological and productive responses of goats of the Moxotó and Canindé breeds, which were supplemented in the Brazilian Equatorial Semiarid region during the hot season in the Caatinga. The research was conducted at the experimental station of the Federal University of Paraíba, located in the municipality of São João do Cariri. Forty goats were used in the finishing phase, 20 of the Canindé breed and 20 of the Moxotó breed, with an average weight of 16.1 kg, kept in an extensive system during the dry season, between the months of December and March. The environmental variables recorded included: air temperature, relative humidity, solar irradiance, wind speed, black globe temperature in both the sun and shade, and the black globe temperature and humidity index. The animals had access to native pasture from 6 am to 4 pm, after which 10 previously selected animals received concentrated supplementation corresponding to 1% of their live weight. Regarding the performance of the animals, this was evaluated based on the initial weight and final weight during the experiment. The physiological parameters analyzed included: rectal temperature (RT), respiratory rate (RR) and surface temperature (TS). The results indicate that the environment in which the animals were was under thermal stress, since the maximum air temperature (Tmax) was above 40ºC in both periods analyzed and that the temperature and humidity index in the sun and shade (ITGU) in the collection periods were 97 and 85 respectively, requiring them to use thermoregulation mechanisms, such as respiratory rate and surface temperature. In Canindé animals, these values were 81.0 movements per minute and 38.5 ºC, respectively, surpassing those of the Moxotó breed. Regarding the productive variables, Moxotó animals presented a higher carcass yield, both hot and cold, with values of 44.7% and 44.0%, respectively. Animals that received supplementation showed a superior performance in all variables evaluated, except for weight loss due to refrigeration, compared to those not supplemented. Thus, it can be concluded that Moxotó animals demonstrated less susceptibility to the semiarid environment, with lower respiratory frequency and surface temperature, and that supplementation improves the productive performance of goats, highlighting how important it is to use this device.