The global livestock sector accounts for 14.5% of man-made greenhouse gases, more than all of the world’s automobiles. In recent years, seaweed as a supplement in the diet of dairy and beef cattle have attracted people's attention, because it may provide a reduction of the enteric methane emissions.
Some seaweed species have the ability to concentrate phlorotannin and bromoforms, the halogenated compounds that can inhibit cobamide-dependent coenzyme M during methanogenesis. C-Lock GreenFeed system users have conducted several scientific validation studies on seaweed, and they've figured out at least three seaweed species that can significantly reduce the cattle methane emissions. On dairy cows, according to a joint research by researchers from the United States and Australia (Roque et al., 2019), feeding Asparagopsis armata, a kind of red seaweed, can reduce enteric methane emission of lactating dairy cows by over 50 percent, but also brought a risk of lower animal performance. Another joint study by American and Brazilian researchers (Stefenoni et al., 2019) showed that another red seaweed species Asparagopsis taxiformis decreased methane emission in lactating dairy cows by 80% and had no effect on animal performance at 0.50% of DMI inclusion rate. Other than red seaweeds, Antaya et al. (2019) reported that feeding Jersey cows with Ascophyllum nodosum temporarily reduced enteric methane and improved feed intake, although there's no significant changes in milk yield or composition but increased milk iodine concentration. On beef cattle a more recent study (Roque et al., 2020) showed that red seaweed (Asparagopsis taxiformis) supplementation reduces enteric methane by over 80 percent in beef steers.
There are more ongoing and upcoming research projects on seaweed in many countries of the world. With more scientific outcomes in the near future, seaweed is very likely to be a game-changer in enteric methane mitigation.