Growth performance and safety of meat from cattle feedlot finished with salinomycin in the diet

Abstract

This study assessed production performance, carcass characteristics, serum parameters, residue depletion of meat, and economic performance during the finishing period of steers in feedlots using salinomycin in their diet. A total of 32 steers were finished in a feedlot on a diet comprising corn silage and concentrate (50:50), with or without added salinomycin (120 mg per animal day -1 ). Study design was completely randomized, with eight repetitions. Results indicated that the use of salinomycin increased both weight gain (1.582 vs. 1.304 kg) and feed conversion (6.16 vs. 7.25 kg kg -1 ). No significant alterations were observed in feed intake (9.52 vs. 9.25 kg animal day -1 ), serum parameters, or apparent diet digestibility. The withdrawal period of 16 h prior to slaughter promoted a lower salinomycin concentration (0.25 µg kg -1 ) in organs and edible tissues, which is below the levels allowed by legislation. Animals finished with salinomycin also exhibited greater warm carcass weight (287.76 vs. 275.81 kg) and better economic performance (profit margin increments of R$ 84.20 per animal). Salinomycin use in feedlot-finished steers promoted both production and economic performance improvements without added implications to either animal or consumer health since there were no significant residues found in any edible tissues. Key words: Growth promotion additives. Feed conversion. Ionophores. Withdrawal period. ResumoObjetivou-se avaliar o desempenho produtivo, as características de carcaça, os parâmetros séricos, a depleção residual na carne e a economicidade da terminação de novilhos em confinamento com salinomicina na dieta. Foram confinados 32 animais com dieta constituída de silagem de milho e concentrado (50:50), adicionada ou não de salinomicina (120 mg por animal dia -1 de alimento (9,52 vs 9,25 kg animal dia -1 ), nos parâmetros séricos e na digestibilidade aparente da dieta. O período de carência de 16 h antes do abate promoveu concentrações de salinomicina inferiores a 0,25 µg kg -1 nos órgãos e tecidos comestíveis, cujos valores estão abaixo dos permitidos na legislação. Animais terminados com salinomicina apresentaram maior peso de carcaça quente (287,76 vs 275,81 kg) e melhor resultado econômico, com incremento de R$ 84,20 por animal na margem de lucro. O uso de salinomicina para novilhos em confinamento promoveu melhorias no desempenho produtivo e econômico, sem prejudicar a saúde dos animais e dos consumidores, pois não houve resíduos significantes nos tecidos comestíveis. Palavras-chave: Aditivo promotor de crescimento. Conversão alimentar. Ionóforo. Período de carência.

Effects of antibiotic growth promoters and concentrate on intake, digestibility, degradability, and ruminal variables in beef steers

“…The lack of effects of antibiotic growth promoters on digestibility (except for digestibility of NDF) was also observed in other studies with the inclusion of ionophores (Mcallister et al, 1994;Neumann et al, 2016) or virginiamycin (Salinas-Chavira et al, 2009). However, ionophores can increase dietary digestibility by increasing the DM retention time in the rumen because of lower voluntary intake, stimulating rumination, and improving the ruminal environment (Ellis et al, 1983).…”

“…The supply of antibiotic growth promoters did not affect the intake DM by steers. Previous studies also showed no effect of LASA (Golder and Lean, 2016), SALI (Neumann et al, 2016) and VIRG (Montano et al, 2015) on intake DM. However, others have reported that ionophores can reduce intake when used in diets with a high proportion of concentrate (Vargas et al, 2001).…”

On the efficacy, innocuity and residual depletion of flavomycin in confined steers

“…Variations in serum parameters during the confinement period are related to age. In a study evaluating these same serum parameters and with animals of the same age, changes were also observed during the confinement period, however the literature reports that the levels of TP, albumin, fibrinogen, AST, GGT are directly influenced by the animal age, because until puberty, there are changes in their metabolism and body composition, such as changes in the rate of bone, muscle and fat tissue deposition (21,22) .…”

Exigências Nutricionais de Zebuínos Puros e Cruzados - BR-CORTE

“…Além disso, redução do CMS de 4 a 6% e melhoria da EA de 6 a 14,8% foram observados em bovinos alimentados com dietas ricas em concentrado contendo níveis de 11 a 50 mg/kg MS de suplementação de salinomicina (Wagner, 1984;Merchen and Berger, 1985;Zinn, 1986a). No entanto, alguns estudos não demonstraram alteração do CMS de bovinos confinados com adição de 11 e 12,6 mg/kg MS de salinomicina (Zinn, 1986b;Neumann et al, 2016) ou 10,6 mg/kg MS de narasina (Gobato et al, 2017). Todavia, vale ressaltar que a narasina e a salinomicina demonstraram ser eficazes na melhora da EA em uma dosagem menor do que a lasalocida e a monensina (Bergen and Bates, 1984).…”