Feeding a bromoform-based feed additive for methane mitigation in beef cattle

Abstract

Bromoform (CHBr₃) is a compound with strong methane-mitigating potential that binds to reduced vitamin B₁₂, thereby inhibiting the cobalamin-dependent methyltransferase step of methane formation. However, bromoform is highly volatile and requires stabilization. This experiment evaluated the methane (CH₄) mitigating effect of feeding Rumin8 Investigational Veterinary Product (Rumin8 IVP), a feed additive containing stabilized bromoform in an oil medium to beef cattle in a cross-over design experiment with two treatments and 10 animals, i.e., Control and Rumin8 IVP (with the active ingredient at 30 mg bromoform/kg dry matter). Methane and hydrogen (H₂) gases emitted were measured using respiration chambers. Rumen fluid and blood samples were collected 3 h post-feeding on the days steers exited the respiration chambers to assess rumen function and plasma biochemical parameters. On average, supplementing with Rumin8 IVP reduced CH₄ emission by 93 % and CH₄ yield by 94 %, and increased hydrogen (H₂) emission by more than 2.5-fold when compared to Control. There was a shift in the dissolved CH₄ and H₂ concentration in the rumen fluid samples consistent with the reduction in the CH₄ production and CH₄ yield. Supplementing Rumin8 IVP had no effect on feed dry matter intake or plasma biochemical parameters. Rumin8 IVP containing stabilized bromoform when fed at 30 mg bromoform/kg DMI is a promising feed additive to reduce enteric CH₄ emissions. However, further investigation is necessary to understand its long-term effect on the animal.