Grass-fed cattle and other ruminants like sheep and goats release methane (CH4) as a result of their slow digestive process. When they belch and fart, they release methane, a powerful greenhouse gas that gets far less attention than carbon dioxide (CO2) as a contributor to global warming.

In fact, methane is about 20 times more efficient in warming the earth's atmosphere than carbon dioxide. The United Nations (UN) suggests that the environmental impact of cattle might be even more damaging than the emissions of cars and trucks combined.

Belching and flatulence by cows are caused by a process called enteric fermentation, which leads to a build up of methane gas in the guts that is in turn relieved by emission. In France, the methane emitted by ruminants is responsible for around 5 percent of the country's greenhouse gases. But one French company, Valorex, has come up a scheme to help cows belch and fart less.

A new diet

Valorex's 'Bleu-Blanc-Coeur' nutrition program gives balances the omega 3 and omega 6 fatty acids in the cow's diet. Scientific research has shown that an unbalanced mix off these fatty acids in animal feed makes cows emit more methane.

Instead of a corn and soy based diet, the cows get a mix of alfalfa, linseed and grass. Valorex spokesman Jean-Luc Besset told DW that by changing the levels of fatty acids in a cow's diet, they can reduce the methane output.

"The more the animal eats rich food, and food with an imbalance between omega 3 and omega 6, the more methane it releases. A cow releases between 600 to 800 liters of methane a day – but with our feed, we've reduced emissions by 20 percent," he said.

The scheme, which is endorsed by the French government and the UN Framework Convention on Climate Change (UNFCCC), requires farmers to follow strict guidelines and test their herds' methane output. Valorex representative Jean-Luc Besset explains that by testing the milk, it is possible to measure carbon output.

"When we analyze the milk, if there's a lot of fatty acid, we're able to estimate the amount of methane produced. This is the scientific explanation for the link between the production of milk, the production of saturated fatty acid, and the production of methane," explained Besset.

Carbon credit incentives

According to the UN Food and Agriculture Organization, livestock contribute around nine percent of human-induced carbon dioxide and 37 percent of methane emissions. The UN has called for a tax on cattle emissions in order to reduce the environmental impact of cattle breeding.

Beef farmer Jean-Marc Laffargue is well aware of the strain cattle place on the environment, which is why he joined Valorex's Bleu-Blanc-Coeur program three years ago.

"The incentive is moral, especially about doing things for the environment, and then having the satisfaction of providing a product to consumers that is better for their health," said Laffargue.

But feed producer Valorex has now created a financial incentive too. In February, the company announced that it is now offering carbon credit rewards for farmers who prevent methane gas from entering the earth's atmosphere. For every measure of methane gas they save equal to one tonne of carbon dioxide, the farmers receive a 100 euro ($128) credit. They can use this credit for discounts on other Valorex products, benefiting both the farmers and the suppliers.

Happy cows

Near the town of Montauban 50km north of Toulouse, Michel Cantaloube produces milk under the guidelines of the Bleu-Blanc-Coeur program. Using the Valorex diet, Cantaloube was one of the first farmers to test the scheme in the southwest of France.

Cantaloube told DW that in addition to the environmental benefits, the cows' milk tastes better and the overall health of his 70 Holstein cows has improved.

"They are sick less often and they are more resilient. They recover from little problems more easily because omega 3 helps them fight diseases," explained Cantaloube. "This means we give them fewer antibiotics … and their fertility has significantly improved."

So far, only Michel Cantaloube, Jean-Marc Laffargue and a handful of other farmers in southwest France have joined feed program. But across the country, participating farmers are already seeing results. So far, The national scheme has managed to prevent 8,365 tonnes of carbon from entering the earth's atmosphere.

That's something milk farmer Cantaloube is tremendously proud of. "The farmer is seen as a major polluter. It's nice to be able to contribute and to say we are making an effort do something," he said. "Doing something good makes us happy."

With the global production of milk and beef expected to double in the next 30 years, bovine burps and flatulence will continue to wreak havoc on the climate. So these farmers aren't passing on their responsibilities by allowing their herds to pass gas.