Dietary supplement reduces methane emissions from cows by a quarter
Cows are a huge source of methane, a potent greenhouse gas, so more and more scientists are looking at how we could tweak their diets for the good of the environment. Scientists at Pennsylvania State University have made yet another discovery in this area, finding that adding a single supplement to the feed of cows can cut their methane emissions by around 25 percent, without affecting their milk-producing capacity.
As cows digest their food, microbes in their stomachs break down the materials and produce methane, which builds up until it is released primarily via the mouth in the form of burps. According to the United Nations' Food and Agriculture Organization, livestock contributes 14.5 percent of all man-made greenhouse gas emissions and the methane they belch out makes up almost half of that, so a small reduction here and there could make a big difference.
Tropical leaves, puffy pink seaweed and fish oils are just a few of the diet supplements that researchers are exploring as a way of putting a dent in bovine methane emissions. The Penn State researchers believe they have found a leading candidate, however, in the form of a compound called 3-NOP.
“3-NOP is the only substance that has worked significantly in reducing enteric methane in cattle and not had unacceptable effects on milk production or quality,” says study author Alex Hristov. “We have tried many things in recent years – including essential oils, oregano and seaweeds – and they either have been ineffective in the long term or need to be investigated further.”
The 3-NOP compound suppresses the activity of an enzyme in the cow’s rumen that is pivotal in the methane production process. The researchers observed this in action during a 15-week study, through which they looked at how the compound affects fermentation in cow bellies along with their lactational performance and the properties of their milk.
Compared to a control group of cows fed a regular diet, those consuming the 3-NOP compound decreased their daily methane emissions by 26 percent. Furthermore, it didn’t impact their lactational performance or the properties of the milk they produced, while actually increasing their feed efficiency per unit of milk yield. And because it is a relatively cheap compound, the researchers are hopeful it could see widespread uptake around the world.
“It could be a game changer, but the question is, will the public accept it,” Hristov says. “It’s a very small synthetic molecule that is metabolized very quickly and falls apart into compounds that are naturally present in the rumen of the cow. Consumer insight studies in the U.S., New Zealand and the Netherlands are showing considerable support for implementing 3-NOP.”
The research was published in the Journal of Dairy Science.
Source: Pennsylvania State University