Combinações de monensina e probióticos em dietas de bovinos de corte terminados em confinamento

Abstract

MEDINA, L.C.M. Combinations of monensin and probiotics in feedlot finished beef cattle diets, 2021. Dissertação - Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, 2021.

The objective was to evaluate the effect of nutritional additives based on yeasts and bacteria, for use in association or potential replacement of sodium monensin on the productive and economic parameters of feedlot finished steers. Forty-eight non-castrated Nellore steers, with initial average body weight of 356.2 ± 17.98 kg, were used, distributed in a completely randomized design. The experiment was divided into two stages, the first being from the beginning (0) to 30 days, where the animals were divided into two groups, with nutritional additives being added to the diet: (1) Monensin or (2) Yeast. In the second stage of confinement (30 – 100 days), each group was subdivided, receiving Monensin or Bacteria, totaling 2 treatments. A diet was prepared with a roughage:concentrate ratio of 30:70 based on dry matter, and the roughage was used with whole millet plant silage. Dry matter intake, feed conversion, gain efficiency, and economic evaluation of the use of additives were evaluated. Periodic weighing were carried out every 30 days. There was no additive effect on dry matter intake, average daily gain and total weight gain of animals in the first experimental stage (0-30 days). Likewise, in the second stage (30-100 days), there was no treatment effect for the consumption and performance variables. The results indicate that Yeast can replace Monensin with no effect on consumption and productive performance in the initial phase of confinement. The combination of the ionophore monensin with bacterial probiotic (Bacillus ssp.) can be a nutritional alternative to maintain the consumption and productive performance of feedlot finished steers fed a diet rich in concentrate.

Keywords: bacteria, confinement, productive performance, yeast, monensin.