The effect of Rumin8 Investigational Veterinary Product-a bromoform based feed additive-on enteric methane emissions, animal production parameters, and the rumen environment in feedlot cattle.

The livestock sector plays a crucial role in mitigating global climate change by reducing greenhouse gas emissions, with enteric fermentation as the largest source. Although various approaches have been proposed to decrease enteric methane (CH₄) emissions, feed additives containing bromoform (CHBr₃) have shown promise with minimal impact on animal production parameters. This study aimed to evaluate the effects of two Rumin8 Investigational Veterinary Products (IVP) containing synthetic CHBr₃ on enteric gas emissions, animal production parameters, and the rumen environment. Twenty-four Angus beef steers were randomly assigned to one of three treatment groups: Control, Oil (8 mL Rumin8 oil IVP/kg DMI), and Powder (1.2 g Rumin8 powder IVP/kg DMI). The Rumin8 oil IVP treatment resulted in a CHBr₃ intake of 32.2 mg/kg DMI, while the Rumin8 powder IVP provided a CHBr₃ intake of 2.0 mg/kg DMI during weeks 1-8. In week 9, a new batch of Rumin8 powder IVP increased the CHBr₃ intake to 17.9 mg/kg DMI. The Oil group exhibited 95.0%, 95.0%, and 96.1% reductions in CH₄ production (g/day), yield (g/kg DMI), and intensity (g/kg average daily gain), respectively, accompanied by 925%, 934%, and 858% increases in H₂ production, yield, and intensity, respectively. Neither treatment significantly affected animal production parameters or rumen environment variables. These findings suggest that Rumin8 oil IVP containing synthetic CHBr₃ has the potential to reduce enteric CH₄ emissions. This warrants further investigation, as this is the first published in vivo study to assess compound efficacy.