Castration procedures and feed management in the finishing phase affect the performance, carcass traits, and meat quality of grazing steers.

Abstract

The objective of this study was to evaluate the effects of different castration methods, body weights at castration, and feeding management practices on the performance, carcass traits, and meat quality of grazing Nellore steers. 60 male cattle were randomly distributed among the following treatments: surgical castration (SC) at 350 kg body weight (BW) and finished in semiconfinement; immunocastration (ImC) at 350, 400, and 450 kg BW and finished in semiconfinement; and ImC at 450 kg BW and finished receiving protein-energy (P-E) supplementation. All steer production phases were carried out in a grazing system with tropical grass, and only the level of supplementation was varied. The animals were subsequently slaughtered, their carcasses were qualitatively and quantitatively evaluated. The measures of animal performance, carcass traits, composition, and physicochemical quality of aged and unaged meat were considered dependent variables. Immunocastration promoted greater (P < 0.05) average daily weight gains (ADG) postweaning, final BWs postweaning, final BWs at finishing, hot carcass weights, carcass lengths, and internal carcass depths. There was no effect (P > 0.05) of ImC weights on the animal performance variables; however, the ImC weight factor influenced (P < 0.05) carcass conformation and the L* component of aged and unaged meat. Semiconfinement promoted greater (P < 0.05) ADGs, final BWs, hot carcass weights, carcass yields, carcass fattening, rib eye areas, subcutaneous fat thicknesses, and L* components of aged and unaged meat. Immunocastration at 450 kg BW and semiconfinement at the finishing phase is recommended for grazing beef cattle production systems that involve the castration of males.