Comportamento e desempenho de novilhos Nelore em sistemas integrados e exclusivo

Abstract

The society has pushed the productive sectors to produce efficiently and less impact on the environment as possible. To satisfy the yearnings have been proposed for the crop-livestock-forest integration systems. Thus, aimed to evaluate the behavior and performance of Nellore steers integrated systems. Treatments consisted of three systems (livestock, crop-livestock and livestock-forestry). The experiment was conducted in Sinop, MT, Brazil, in a randomized complete block design with four replications and two seasons (transition dry/rainy and rainy) evaluated September 19, 2015 on January 10, 2016. Was used Nellore steers with average initial weight of 344±10.7 kg in continuous stocking and variable stocking rate, weighed every 28 days of fasting. The agronomic performance was evaluated through the forage mass and forage accumulation rate, that whatever system the rainy season had a higher mass and forage accumulation rate. The microclimate was evaluated at times grouped every two hours and had lower air temperature and black globe temperature and humidity index (THI), black globe temperature and humidity (BGT) and radiant heat load (RHL) in the livestock-forestry system and its shade. The behavior was evaluated by visual observations every 10 minutes from 7 am to 17 hours and grouped every two hours. The highest grazing time was recorded during the hours from 9 to 13 and after 15 hours, regardless of the system. Rumination occurred more frequently in the time from 13 to 15 hours, during the rainy season and shadow on livestock-forestry system. The average daily gain and stocking rate were higher in rainy season of the regardless system. Weight gain per area was higher in rainy and crop-livestock system. Therefore, it is concluded that during the rainy season there is a higher accumulation of forage, reducing thermal comfort indices and increased animal performance.