Seaweed-Derived Feed Additives for Enteric Methane Mitigation in Cattle: Efficacy Evidence, Economic Incentives, and Policy Pathways for Smallholder and Commercial Dairy Systems

Abstract

The emissions from enteric methane by the world's 1.5 billion cattle is one of the largest and least tackled sources of agricultural GHGs. Livestock emissions are a critical factor in near term climate outcomes as methane has a global warming potential of approximately 80 times more than carbon dioxide over a 20 year time horizon. This article explores an emerging mitigation pathway natural, seaweed based feed additives that inhibit the formation of CH4 in the rumen. It reviews peer-reviewed trials and meta analyses, dissects the biological mechanism of bromoform containing red seaweed to inhibit methanogenesis, and examines figures of actual reductions, which have been as high as 80% or more in some instances depending on the dose and conditions, as well as the economic case for adoption by smallholder farmers, dairy cooperatives, and corporate producers. The piece also places this technology in the context of changing regulations, such as the first ever livestock emissions tax in the world, which will come into effect in 2030, and the specific advantage for countries with a high number of cattle. Most importantly, it highlights unanswered questions regarding long term effectiveness, animal productivity, food safety and cost. The goal is to provide the public, policy makers and farming communities with fact based and balanced information on a technology that could be important for climate mitigation and for rural livelihoods as well.