Fattening performance and carcass traits of implanted and supplemented grassfed bulls

Abstract

Ninety-nine uncastrated males were randomly distributed into four grazing groups to examine variation in growth and carcass traits, due to the implant regime [Implantation of 72 miligrams (mg) of Ralgro® at day (d) 0 followed by its reimplantation at d 90 versus implantation of Revalor® at d 0 followed by 72 mg of Ralgro® at d 90)], and suplementation type [mineral supplementation (MS) versus strategic supplementation (SS)]. With a 2 x 2 factorial arrangement, the analysis of variance included the treatments and their interaction (implant regimen x supplementation) as fixed effects, and the breed type as a random effect. The interaction was not significant; neither did the implant regimen on any growth trait (P > 0.05). Compared to MS, the SS group had a greater daily weight gain (779 vs. 541 grams; P 0.05). The use of aggressive implant regimens to improve growth or carcass characteristics of grazing bulls is not justified. SS is a feasible practice to improve fattening performance of grazing bulls but no beneficial impact on their carcass quality was expected.

Keywords

• Strategic supplementation
• implants
• bull
• beef carcass
• Brahman