My wife Sue and I just returned from a two-week vacation that included a road trip through several western states. In addition to wildlife, we noticed thousands of little methane factories scattered across public and private lands.
I’m talking about cattle, of course, and their role in climate change. I have to admit that gaseous emissions from cows seems like a often-told joke. (Question: What do you call a cow fart? Answer: dairy-air.) But methane from cattle is a serious problem with worldwide effects. The millions of dollars in research being conducted to reduce bovine emissions is strong testimony to the level of concern.
Stories I have read on this topic often relate the amount of gases coming from a single cow to the effects of driving a car.
In fact, so much has been written about cow farts and climate change — mainly for the sake of humor — that I thought that the rear of the cow was the source of the biggest problems. It turns out that far more methane gets released from the other end, in the form of gaseous burps from the mouth.
A recent study, funded by NASA’s Carbon Monitoring System, concluded that the worldwide problem of methane from cattle is 11 percent worse than estimates reported in 2006 by the Intergovernmental Panel on Climate Change. The new study involved more precise estimates of methane production in a cow’s gut as well as that produced during manure management.
In the U.S. and Canada, methane production from total cattle operations was found to be 24 percent higher than previous estimates, largely because of open-air manure management. In Europe, more farmers are using methods that contain the methane, often using it for energy. The study was published in the journal “Carbon Balance and Management” and reviewed in “Popular Science.”
As greenhouse gases, methane is more potent than carbon dioxide, yet the amount released into the atmosphere is far less. The international goal is to reduce emissions of both gases to slow the average warming of the planet.
Researchers have found that feeding cattle different types of grains or silage can reduce the amount of methane produced by bacteria in the stomachs of cattle. Feedstocks effective in reducing methane include garlic and onions, but a major problem for dairy farmers is that those products can change the taste of the milk that cows produce.
One farm in Vermont began supplementing its cattle feed with cooked flax. The result was not only less methane coming from the cows, but the milk itself contained a higher level of beneficial omega 3 fatty acids.
Ongoing research is finding that a diet for cattle high in carbohydrates and/or fats can result in less methane production. Using ground or pellet forms of forage may reduce the time of passage through the cow, thus reducing methane production. See news release from the University of Nebraska – Lincoln.
A story published last week in the online “Feed Navigator” discusses the complexity of the issue. Changing feedstocks can affect cattle and their emissions in different ways. One must account for the effects of growing the feedstocks, handling the manure generated and the health for both the cattle eating the forage and the humans consuming the milk or meat, according to the article by Aerin Einstein-Curtis.
“We have it very tight where we follow the diets, and we know the diets produce a certain type of manure, with certain emissions, and this is what you get out of it,” said Michael Wattiaux, professor of dairy systems management at the University of Wisconsin, who was quoted in the article. “One thing that I could see in terms of practical recommendations is maybe you want to have the agronomist and soil scientist and nutritionist all in the same room at the same time.”
