UC Davis

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.