Características de termorregulação de bovinos Nelore confinados utilizando dietas com óleos essenciais e submetidos ao estresse por transporte

Abstract

The aim of this study is to evaluate the effect of supplementation with essential oils (EO) on the thermal regulation of cattle during the transport period and feedlot. The experiment was carried out in two phases: transport and feedlot. 48 Nellore animals were used, randomly outlined in 2 treatments in the first phase: protein supplement with essential oil (EO); and protein supplement without essential oil (WEO) and in the second phase in a 2 x 2 factorial arrangement (transport or not x supplemented with essential oil or not). In the first phase the animals were subjected to a trip of approximately 12 hours in cattle trucks and in the second phase the animals were confined for 99 days in individual stalls. The animals were weighed and body surface temperature (BST), respiratory rate (RR), rectal temperature (RT) was collected in both phases. Data loggers were installed in the trucks, as well as in the feedlot facilities, for collecting relative humidity, dry bulb temperature (DBT) and dew point temperature.Data on daily dry matter intake (DMI) were collected during the feedlot phase. In Phase 1, no EO effects were found under the thermoregulatory characteristics, however, it was possible to observe the physiological stress of the animals after the landing management, verifying lower BST and RT in animals not transported. In phase 2, likewise, no effects were observed between EO treatments. However, it was possible to observe a change in the DMI in relation to DBT, behaving in an inversely proportional way.