PSXIV-39 Use of flamocycin, narasin and salinomycin on performance of Nellore yearling bulls fed with high forage diets

Abstract The aim of this study was evaluating the effects of different feed additives on performance of yearling bulls fed a high forage diet. One hundred and sixty-four Nellore (Bos indicus) yearling bulls were assigned to a complete randomized block design, according to of their initial body weight (BW) (298.95 ± 2.49; 10 pen/treatment; 4 animal/pen). Yearling bulls were fed daily and diets were composed of 96% of coastcross haylage and 4% of ground corn, used as the delivery vehicle for the additives. Once a day, the concentrate and forage were offered separately. The forage was offered after the entire consumption of the concentrate. The experimental diets consisted in: CON = Control (no feed additive); FLA = 3ppm of Flavomycin; NAR = 13ppm of Narasin; SAL = 20ppm of Salinomycin. The experimental period lasted 140 d and the yearling bulls were weighted at 0, 28, 56, 84, 112 and 140 d, after a 14h feed and water restriction. The orts were recorded to determine the dry matter intake (DMI). All data were analyzed using the MIXED procedure of SAS and the LSMEANS option was used to generate individual means. Tukey test 5% was used for comparisons. There was a treatment effect on DMI (CON: 6.59b; FLA: 6.53b; NAR: 7.1a; SAL: 6.42b kg/d; SEM = 0.19; P < 0.01), ADG (CON: 0.792b; FLA: 0.842b; NAR: 0.907a; SAL: 0.813b kg; SEM = 0.02; P < 0.01) and final BW (CON: 408.27b; FLA: 411.36b; NAR: 424.69a; SAL: 407.91b kg; SEM = 2.56; P < 0.01). There was no effect on feed efficiency (P = 0.41). In summary, the narasin inclusion increased DMI, ADG, and final BW in comparison with the other additives.