Effect of bromoform-based feed additive on methane emissions and performance of Nellore cattle in feedlot backgrounding and finishing phases

Abstract This study evaluated the effects of a bromoform based feed additive (BBFA) on growth performance and enteric methane emissions in Nellore cattle during feedlot backgrounding and finishing phases. Ninety-six Nellore bulls (10 ± 2 months old, body weight (BW) 315 ± 23 kg (block 1), and BW = 360 + 7 kg (block 2)) were allocated to one of two treatments: CONTROL (basal diet) and BBFA (basal diet plus BBFA (to target 23 mg bromoform/kg dry matter)). Bulls were housed in pens (n = 6 animals/pen) and monitored over 218 days (108 days backgrounding, 110 days finishing). Performance parameters were measured in all bulls, while enteric methane emissions were assessed in a subset of 36 animals using the sulphur hexafluoride (SF6) tracer technique. Supplementation of the BBFA did not influence dry matter intake (DMI), weight gain or feed efficiency (P > 0.05). Compared with control, BBFA decreased methane production and yield by 26% and 25%, respectively, during backgrounding (P < 0.001). While, in the finishing phase, BBFA supplementation resulted in reductions of 58% in methane production, 59% in yield, and 60% in intensity (P < 0.001). These findings demonstrate the potential to supplement the BBFA throughout the lifecycle of cattle in Brazil, reducing methane emissions without any detrimental impacts on productivity.