Cows are notorious producers of the greenhouse gas methane. But with feed adjustments, targeted breeding and improved manure storage, these emissions can be significantly reduced.
The Dutch dairy cow is a controversial animal. When it burps, farts and poops, it produces methane, a powerful greenhouse gas that contributes to global warming. In our fight against climate change, the cow’s methane emissions should be significantly reduced. But is that possible? And how? Theun Vellinga, a Wageningen scientist specializing in livestock research, is optimistic. According to him, there are a few buttons we can turn to reduce the cow’s methane emissions. “We can even halve the climate impact of the Dutch dairy cow,” he says in an interview with Scientias.nl.
Methane emissions from milk
Worldwide, the production of one kilo of milk releases 2400 grams of CO2 equivalents (a measure by which greenhouse gases such as nitrous oxide and methane can be compared to carbon dioxide). Thanks to more efficient production methods, that number is a lot lower in the Netherlands: 1150 grams of CO2 equivalents. Still, that is too much. If we want to meet the climate agreements, those emissions must be reduced further, by around 30 to 50 percent in the coming period up to 2030. We can easily achieve that, Vellinga thinks. If we just turn the right knobs.
(1) Feed
The first button we can turn has to do with the cow’s diet, Vellinga explains. Grass is on the basic menu. When grass is converted in the rumen, the greenhouse gas methane is created. However, there are ways to inhibit this methane production. “Colleagues have done a lot of research into ways to suppress methane formation and three promising agents have emerged from this,” says Vellinga. “Nitrate, vegetable oil and the feed additive 3NOP.” The latter in particular is promising. Because although there are some disadvantages to adding nitrate and vegetable oil, methane inhibitor 3NOP appears to be particularly effective without any catches. “With this agent we can achieve a methane reduction of 30 percent,” says Vellinga. “Moreover, you only need to feed small quantities, just a few grams per day. Analyses have also shown that no residues of the agent end up in the milk. In short, we do not expect any negative effects. It really is a great solution.”
What is holding farmers back? “The product is not free,” Vellinga emphasizes. “That is currently the bottleneck. It increases the cost price of milk by about one cent per liter. That does not seem much, but for a company that produces one million kilograms of milk, that amounts to 10,000 euros per year. And who is going to pay for that?”
Higher cost price
According to Vellinga, this is the crux of the matter. “When car manufacturers were required to equip their cars with a catalytic converter, they could pass the price on to the customer,” he explains. “Farmers cannot simply increase the cost price of milk. Supermarkets will then get the milk somewhere else. This is the tricky thing in agriculture. The costs of production cannot yet be recovered from the product. The farmer in fact has no market power; that lies with the large food processors and the retail sector.” Although there may be a role for the government here, international food companies are also currently taking their responsibility. A good move, Vellinga believes. “A few large chains are already investing money in projects to reduce greenhouse gas emissions in livestock farming. They are not throwing the problem over the hedge to the farmer, but are looking at how they can work together to ensure that their products have a smaller ecological footprint.”
(2) Genetics
A second promising button that can be turned is ‘genetics’. How does that work? “You can breed cows that produce less methane,” says Vellinga. “Research has shown that the amount of methane produced varies per cow. These are small differences, but methane production can be reduced by a quarter to three quarters of a percent per year in this way. So if you breed in a targeted manner for years in a row, my colleagues expect that you can ultimately achieve a methane reduction of five to fifteen percent.”
Long breath
However, this is a long-term story. “If you feed a cow the methane inhibitor 3NOP, you will have an effect tomorrow, so to speak. However, if you select suitable bulls and start breeding in a targeted manner, you are talking about a process that takes 30 to 35 years before you have achieved a methane reduction of fifteen percent.” According to Vellinga, this is no reason to just leave it at that. Ultimately, it should be a combination of both, he thinks. “Moreover, targeted breeding is cheap: there are few costs involved.”
(3) Most
Finally, you can tinker with the manure. “The manure and urine are now still combined in the manure cellar under the stable,” says Vellinga. “This creates methane. We are now looking at how we can remove the manure more quickly and store it in a closed space outside the stable. In this case, the manure should actually be removed from the floor as quickly as possible and taken to the closed storage. There, various methods can then be used to prevent it from ending up in the atmosphere. This way, you can significantly reduce the methane emissions from the manure, think of a reduction of 80 to 90 percent.”
Renovation of stable
This is also a long-term solution. “It requires a major renovation of the barn. And a farmer who renovated his barn last year is not going to do it all over again. Barns are often only written off after 25 to 30 years. The new barn is not even much more expensive. However, there are costs associated with the installations that prevent methane from being released into the atmosphere. An important condition is that these adjustments can only be implemented after the current barn has reached its end of life. And so this solution is also a long-term one.”
Methane: a powerful greenhouse gas
Methane is considered one of the most important greenhouse gases. Although the gas is present on earth in smaller quantities, it is much more powerful than CO2; as a greenhouse gas, its effect is even 28 times stronger over a period of 100 years. In addition, methane is more volatile, which means that it has a shorter lifespan than carbon dioxide. After nine years, approximately half of the methane pumped into the atmosphere is left. The concentration decreases year after year, until after sixty years there is almost nothing left in the atmosphere. CO2, on the other hand, can persist for centuries. The amount of methane in the air has increased approximately sixfold since 1750. Therefore, even smaller quantities have a major effect on the atmospheric temperature. Most of the methane on earth is produced by micro-organisms that convert organic material into methane in areas with low oxygen levels. For example, think of marshland or agricultural land such as rice fields. The cow’s rumen is also such an oxygen-free situation in which methane is produced. The rest comes from fossil fuels such as natural gas.
Methane reduction
Which solution ultimately provides the greatest methane reduction? “By reducing rumen emissions,” Vellinga answers resolutely. “If you look at the total methane emissions on dairy farms, 80 percent comes from the rumen and 20 percent from the manure.” According to the researcher, the cows’ diet and breeding program should therefore first be examined carefully. Incidentally, Vellinga emphasizes that in the search for ways to make cows more climate-friendly, the focus should not be entirely on methane reduction. “Of course that is important, but you do not want to implement a solution that on the one hand reduces the cow’s methane emissions, but on the other hand actually causes more CO2 or ammonia emissions. Then you still haven’t solved anything. For example, it is possible to extract methane from stables. But the equipment you need for that is a major energy guzzler. You then emit a lot of CO2 to capture some methane. So we really went looking for measures that do not have negative effects elsewhere. It has to work well on all levels – or at least not work against you.”
Climate-friendly cow
All in all, Vellinga proves that it is indeed possible to make the ‘polluting’ cow a lot more climate-friendly in a responsible way. However, every solution also has its own challenges. Nevertheless, the researcher believes that we can halve the climate impact of the cow in this way. “It is really feasible,” he says. “On the one hand because it is technically possible. But also because there are more and more parties who want to cooperate. We are currently working with two dairy companies, one of which wants to halve the emission of milk in five years and the other in 2030. Ultimately, we want to scale this up to all dairy farms throughout the Netherlands. But this is a process that takes time, because with all these adjustments you ask quite a lot of a farmer. Nevertheless, we see that many farmers are motivated. Ultimately, we have to do something about the emissions. But how? And can they continue their business? These are the concerns they have.”
Vellinga, however, proclaims a positive message. And that is that the climate-friendly cow is not a mythical creature, but precisely the opposite: a feasible animal that may soon be grazing on Dutch grasslands. “It is possible, but we have to do something for it,” he emphasizes. “It does not happen automatically. Some solutions cost money and other techniques have only recently been developed. We will have to do something with that.” Nevertheless, according to Vellinga, the future looks bright. Because according to him, the climate-friendly cow will be native to the Netherlands before 2050.
