Evaluation of antibiotic growth promoters on mineral mixtures for grazing beef cattle

• Grant number: 09/00197-3
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2009
• End date: February 28, 2011
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Moacyr Corsi
• Grantee: Moacyr Corsi
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

This project aims to develop one of the strategies to increase yield and sustainability of beef cattle production. Although ionophore and other antibiotic as growth promoters for ruminants is an extensive studied subject, the adoption of this technology on grazing cattle farms in Brazil is inexpressive. The objective of this research is to evaluate an antibiotic delivery method via mineral mixture (MM). A pre-experiment will be conducted to evaluate intake of MM with antibiotic additives. This phase will last 30 days using 120 animals divided in 2 blocks and 4 treatments: 1) control - MM only; 2) MM with salinomycin; 3) MM with virginiamycin plus 15% soybean meal and 4) MM with virginiamycin. After the pre-test, performance trials Will be conducted during 120 days. Three hundred and thirty calves will be divided in 5 blocks and subjected to the same treatments used on the pre-test, with adjustments on salt formulation suggested by its results. Variables to be monitored are: weight gain; MM intake; individual MM intake using lithium as a blood marker; volatile fatty acids profile and pH of the rumen content; and coccidiosis incidence. With the results of this research it is expected to demonstrate the viability of using an antibiotic on mineral mixtures as growth promoter for grazing beef cattle - a technology that can increase profitability and sustainability of grazing systems. Besides that, variables monitored will allow discussion of the results on a manner that can contribute to exploration of the conceptual knowledge on the research area. Methods to be used can contribute to progress on ruminant nutrition research techniques. (AU)