Effects of antibiotic growth promoters mixed with mineral supplement on growth performance, ingestive behavior, and mineral intake of grazing bulls

Marcelo Vedovatto,José Mauro Da Silva Diogo,Gumercindo Loriano Franco,Clayton Quirino Mendes,João Artêmio Marin Beltrame,Cássio José Da Silva,Sergio Lucio Salomon Cabral Filho,Marcella Cândia D'Oliveira

doi:10.1590/rbz4820190114

Abstract

ABSTRACT The objective was to evaluate the addition of antibiotic growth promoters to free-choice mineral supplement on ingestive behavior, mineral intake, and growth performance of grazing bulls. Sixty Nellore bulls [initial body weight (BW) of 219±17.8 kg and 15±2 months of age] were divided in 12 marandu grass paddocks. The treatments were: mineral supplement (control), mineral supplement + virginiamycin (VIRG), mineral supplement + lasalocid sodium (LASA) and mineral supplement + salinomycin sodium (SALI). Mineral supplements were formulated with target intake [...]

Highlights

ABSTRACT - The objective was to evaluate the addition of antibiotic growth promoters to free-choice mineral supplement on ingestive behavior, mineral intake, and growth performance of grazing bulls
Free-choice mineral supplementation intake by bulls has a high variability, and this impairs the regulation of the intake of antibiotic growth promoter additives
The free-choice mineral supplement is an alternative for the administration of antibiotic growth promoters that potentiate ruminal fermentation

Summary

Introduction

The free-choice mineral supplement is an alternative for the administration of antibiotic growth promoters that potentiate ruminal fermentation. Ionophores such as lasalocid and salinomycin sodium, and virginiamycin antibiotic, are noteworthy. They act mainly against gram-positive bacteria present in the rumen, improving ruminal fermentation efficiency (Page, 2003). With the selection of gram-negative bacteria in the ruminal environment, under the same diet, animals produce more energy due to the increase of fermentative efficiency, mainly by the increase of propionate production, and reduce ammoniacal nitrogen production, which can generate improvements on feed efficiency, in addition to reducing the environmental impacts provoked by cattle production, since CH4 emission is reduced (Page, 2003). The beneficial effects of using antibiotic growth promoters in feedlot or grazing cattle that consume concentrated supplementation have already been extensively proven (Bretschneider et al, 2008; Golder and Lean, 2016). The use of mineral supplement as a vehicle for supplying antibiotic growth promoters has been widely employed, but with few studies proving its beneficial effects (Rode et al, 1994)

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