Development of algae based functional foods for reducing enteric methane emissions from cattle

Summary

​Marine and freshwater macro algae have the potential to be used as alternative protein and energy sources in ruminant diets.

Twenty macroalgae have now been assessed in vitro to identify nutritional and antimethanogenic properties. At 17 % of organic matter (OM) in the assay, some macroalgae were shown to reduce in vitro methane production.

At low inclusions (<5%), only asparagopsis taxiformiswas found to be an effective antimethanogenic agent with the virtual elimination of methane and minimal effect on fermentation. asparagopsis sp. accumulate more than 100 low molecular weight metabolites containing bromine, iodine and chlorine, in specialised cells and these bioactives induce significant antimethanogenic effects in vitro. The effect of a. taxiformis at 2 % of om in combination with other alga was dominant with little benefit attributed to additional macroalgae at 5 % of om. oedogonium undulatum had little effect on in vitrofermentation at doses ≤ 25 % of om, however this freshwater macroalgae is rich in protein, beneficial lipids and has unique potential for on-farm production. among the 20 macroalgae evaluated a. taxiformis was found to be the most suitable for an abatement methodology for ruminant livestock. at 2 % of om it had minimal effect on in vitro fermentation.

Due to the nature of the bioactives contained in a. taxiformis, livestock productivity benefits will be realised by feeding algal biomass as a supplement, and so achieve a reduction in ge losses associated with methane production. abatement benefits will only be achieved by the agriculture sector when commercial scale supply of asparagopsis spp. and favourable cost of production is realised.></5%),>