The introduction of seaweed to cows' feed can reduce methane emissions by 58%, according to research from UC Davis. The addition of seaweed to the diet of cattle helped to block methane production during enteric fermentation in the digestive process. Livestock accounts emissions equivalent to over seven gigatons of CO2 annually, as much as the transportation industry. If UC Davis's technology could be used throughout the global meat industry, nearly two gigatons of emissions a year could be saved. While early results are promising, one barrier could be the problem of producing sufficient amounts of seaweed to meet global demand.
Why does this matter? The UC Davis study focuses on supplementing cow feed with the Asparagopsis genus of seaweed, or “red algae”. More recent work from the University of Vermont is focused on determining which seaweed species offer the biggest emissions-cutting benefit; along with quantifying potential health benefits for the animals. One issue is whether enough seaweed would realistically be able to be cultivated to satiate demand from the cattle industry. Another is the carbon footprint of growing and transporting seaweed to farms. This may be less of an issue in geographies such as Australia, where Asparagopsis taxiformis grows abundantly off the Queensland coast. Elsewhere, Asparagopsis may have to be cultivated on land with sterilised and aerated seawater, which would increase environmental impact “upstream”. However, a new customer, in the shape of the cattle market, could aid growth in the seaweed aquaculture sector, providing opportunities for businesses able to cultivate Asparagopsis in the ocean using, for example, seeded rope techniques – a practice becoming increasingly economic. If seaweed cow feed becomes a large-scale industry, such aquaculture techniques would be necessary, as relying on harvesting wild seaweed to meet demands of the cattle industry would deplete oceans and have ecological consequences. As with many environmental issues, trade-offs will need to be considered between the environmental costs of growing the seaweed, then transporting it, versus the amount of methane it will save. The final uncertain factor is whether cows will actually like eating it, though early indications have been positive.
Source: Farming Portal