Respostas comportamentais e fisiológicas de ovinos Santa Inês sob diferentes horários de fornecimento da dieta

Abstract

This study aimed to evaluate the effect of different supplies timetable on physiological parameters (rectal temperature, respiratory rate, skin temperature and hair coat surface temperature and sweat rate), intake and digestibility of nutrients, ruminal parameters (pH and ammonia) and ingestive behavior of Santa Ines sheep, under feedlot conditions in a region of hot and humid weather. Five male sheep non-castrated of initial average weight of 27± 3 Kg, and fitted with rumen cannula, were distributed in 5x5 Latin square. The diet was provided twice daily and the experimental treatments were the different times of providing second meals: 13:30h, 15:00h, 16:30h, 18:00h, 19:30h. For all treatments the first meal was offered at 7:00h. The environment was monitored 24 hours from the weather station installed inside the barn, to determination of thermal comfort indexes: THI (Temperature-Humidity Index), BGHI (Black Globe-Humidity Index) and TCI (Thermal Comfort Index-specific for sheep) that showed ranges from 72 to 83, 72 to 86, 30 to 42, respectively. Physiological variables: rectal temperature, skin temperature, hair coat surface temperature, and sweat rate were not affected by the different supplies timetable (P> 0.05). There were significant effects of different supplies timetables of the second meal on the respiratory rate, which in this study was the physiological parameter most important to animals to dissipate the endogenous heat raised by diet metabolism. To the other parameters studied, intake and digestibility of nutrients, and ingestive behavior, there were no effects of different supplies timetables (P>0.05). The rumen parameters pH and ammonia were not affected by different timetables (P>0.05). For Santa Ines sheep under feedlot conditions in a region of hot and humid weather it is recommended either supplies timetable tested in this study.