Livestock production contributes between 11% and 19% of global greenhouse emissions. The largest source of these emissions is enteric methane, the gas produced during digestion as the feed ferments in the animal’s stomach and is released mainly through burping. There are other cattle-related emissions as well, including the release of nitrous oxide from manure.
There are a number of strategies being pursued aimed a reducing these emissions. For example, feeding seaweed to cattle has been shown to reduce methane emissions with limited impact on the quality of meat and milk.
A new study led by McGill University in Montreal shows that supplementing dairy cow diets with microencapsulated B vitamins can significantly reduce greenhouse gas emissions while actually increasing milk yield and quality. Using the feed additive was shown to cut global warming potential – which is an internationally standardized measure of climate impact – by 18% across seven countries studied.
It is difficult to provide vitamin supplements to cows because they mostly degrade in the rumen – the cow’s second stomach – before they can be fully absorbed by the animal. By microencapsulating the B vitamins, they bypass the rumen and are released in the small intestine, where absorption is highest.
The study looked at the quality of the milk produced, the effects of different feeds in different locations, and the cradle-to-grave environmental impact of the supplement use. The environmental cost of producing and transporting the additive was minimal.
The next step is modeling national-level adoption scenarios as well as the possibility of using other feed additives that more aggressively target methane emissions.
