Ácidos graxos no desempenho e nas respostas imunológicas de bovinos Nelore confinados

Abstract

The objective of this work was to evaluate the addition of natural and protected lipid sources on the performance and immune responses of Nelore cattle feedlot. A completely randomized design was carried out with repeated measures in time and three treatments, which were: without additional source of lipid (CONTR); with natural lipid source (cottonseed cake) (GDESP); and with rumen protected lipid source, rich in polyunsaturated fatty acids (GPROT). The study was divided into two phases: preconditioning and feedlot of 120 noncastrated Nelore cattle (24 pens, 5 animals per pen, and 8 pens per treatment). The GDESP treatment provided greater weight gain in the preconditioning phase, and, during the feedlot period, there were no differences among treatments for performance, carcass traits, and disease incidence. The highest plasma concentrations of TNFα, IL-1β, haptoglobin, and ceruloplasmin occurred in the CONTR treatment. Lipid supplementation to the diet, regardless of the source, improves the performance and enhances the immunological system of confined Nellore cattle.