Researchers from the US and Australia have published results stating that red seaweed supplementation can reduce enteric methane from beef steers by more than 80%.

Asparagopsis taxiformis is the seaweed of interest, which was fed as part of a trial on 21 Angus-Hereford beef steers.

Steers received high (0.5%) and low (0.25%) treatments, while there was also a control group.

The steers were fed three diets - high, medium and low total mixed rations (TMRs), which represented the life stage diets of the steers.

Over 147 days, the low and high treatments reduced the enteric methane produced by 45% and 68% respectively.


Looking at the differences between the diets fed, where a low-forage TMR ration was supplemented with a low rate of seaweed, it resulted in a methane reduction of 69.8% and where it was treated with a high rate of seaweed, a methane reduction of 80% was reported.

Hydrogen and carbon dioxide increased as methane emissions decreased.

No change in taste

Very importantly, there were no differences reported in average daily gain, carcase quality or other qualities such as consumer taste preferences.

Dry matter intake did decrease with treatment. However, feed conversion efficiency was found to increase when compared with the control.

The researchers concluded that the persistent reduction in methane suggests “that this is a viable feed additive to significantly decrease the carbon footprint of ruminant livestock and potentially increase production efficiency”.