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.
Silva et al. (Fri,) studied this question.