Effects of including autolyzed yeast in the finishing of feedlot steers

Abstract

Functional additives, such as autolyzed yeasts, have been used to achieve greater production efficiency and animal health. These compounds are also alternatives to the use of performance-enhancing antimicrobials. The objective was to evaluate the productive performance, ingestive behavior, apparent digestibility of feed DM and the carcass characteristics of beef steers finished in feedlot receiving autolyzed yeasts in the diet. The experimental design was randomized blocks, consisting of three treatments and six repetitions, where each repetition was represented by a stall with two animals. 36 bulls, 1/2 Angus × 1/2 Nelore blood, from the same herd, with an average age of 11 months and an average body weight of ± 330 kg were used. The treatments were as follows: CON - yeast-free diet; Y4 - yeast diet (4 g animal day-1) and Y7 - yeast diet (7 g animal day-1). The product used is a functional ingredient containing the yeast Saccharomyces cerevisiae. The inclusion of autolyzed yeasts resulted in greater daily body weight gain and better feed conversion in the initial feedlot phase. The apparent digestibility of DM of diets containing autolyzed yeast was superior to the control diet, and its use did not interfere with the animal ingestive behavior. Supplementation with autolyzed yeasts at the inclusion level of 4 g day-1promoted better results in the finishing of feedlot steers, and that the supplemented groups (4 g animal day-1and 7 g animal day-1) achieved the same degree of carcass finishing, higher than the control group.