How do you let a cow graze in such a way that it emits less?

Dairy farmer Leendert van Staalduijnen looks out over his pastures from behind a fence. Beside him is grazing specialist Mark de Beer. Van Staalduijnen tells him where his plots are and how he will let his cows graze on them in the spring and summer months.

Van Staalduijnen’s dairy farm, with about a hundred cows, is located in a special place: the Staverden estate, in the middle of the Veluwe. His father and great-grandfather already kept cattle on the monumental 100-year-old tenant farm.

The location is also vulnerable. Walk down the driveway, and you walk into a nitrogen-sensitive forest. Walk through the stables and after a few hundred meters you are on the moor. Wherever the wind blows, the nitrogen from Van Staalduijnen’s cows soon lands on a nitrogen-sensitive Natura 2000 area.

Van Staalduijnen strongly feels that he must reduce his company’s nitrogen emissions in order to maintain his business. Good chance that he is a peak loader, he says. He doesn’t think about quitting – at least not aloud. “There is nothing more beautiful than working here with the cows.”

The possibilities to reduce its nitrogen emissions are limited. Adjusting the cow sheds to reduce emissions is not possible, because the monumental shed may not be renovated. Getting rid of even more cattle is not an option if he also wants to earn a living.

And so Van Staalduijnen desperately needs the advice of grazing specialist De Beer. The farmer wants to let his cows go outside for longer and more often, because more grazing leads to lower nitrogen emissions. Ammonia is only formed when manure and urine come together, and that happens less in the pasture. But how does Van Staalduijnen get his cows outside even more?

Cows that go out to pasture more often: that sounds easier than it is

At the gate, De Beer listens intently to Van Staalduijnen’s story. He nods in agreement with his explanation and fires off short questions in between. How far is the walk to the back lot? Are there enough water bowls along the route? How do the cows rotate across the fields? How is the climate in the barn when it is very sunny? What about udder health?

Cows that go out to pasture more often: that sounds easier than it is. Last year, Van Staalduijnen’s animals spent more than a thousand hours in the meadow: six hours a day times 170 days. This should be done between April and October. Outside that period, the ground is too wet to support the cattle. Van Staalduijnen cannot just put his cows in a meadow, because the most nutritious grass will have been grazed after a day. He has to constantly move the herd if he wants to get as much food as possible from his pastures.

More grazing also means more work for Van Staalduijnen. De Beer advises him on rotation systems and the layout of the plots. One option is to send the cows out twice a day: early in the morning and around dusk. That is a lot of work, says De Beer. “It is also important what the farmer wants to do. I don’t want Leendert to become a slave to his own system.”

Giving too much protein

Van Staalduijnen has been part of the Praktijkbedrijven Netwerk for a year now, an initiative of Wageningen University & Research (WUR) and farmers’ interest organization LTO Noord. The network, with about a hundred companies, is investigating how nitrogen emissions can be reduced with ‘management measures’. Not with expensive technology or by handing in part of the herd, but by farming in a different way. The network helps livestock farmers with coaches and experts such as De Beer.

More grazing is one of the solutions and can lead to a nitrogen reduction of about 5 to 10 percent. Other options are more efficient feeding, or cleaning the house with plenty of water. Agricultural technologist Gerard Migchels of WUR, one of the initiators, thinks that nitrogen emissions can be reduced by a quarter through these types of measures. It’s not easy, he says. “It requires craftsmanship from the farmer.”

Take the feed. Farmers now often give cows more protein, in the form of concentrates, than the animals need. “Farmers are afraid that their cows will give less milk if they get less protein, but too much protein also means more ammonia formation.” One reason, says Migchels, is that the average farmer has little access to independent expertise: the concentrate supplier is often also the feed advisor.

In his stable in Riethoven in Brabant, Leo Coppens, a dairy farmer who is also part of the WUR and LTO Noord network, is standing next to a machine that gives his cows concentrates. The portion is measured automatically: each cow is recognized by a chip in the collar. The machine knows exactly how much protein the cow has already received and how much protein she is allowed. A cow that has just calved produces a lot of milk and needs more protein. These are data that Coppens closely monitors.

Coppens has already achieved success: he is now at 162 grams and eventually wants to get to 145 to 150 grams of protein per cow per day. That goes step by step, a few grams less each time. “Then we look together with the food advisor and the vet to see if we run into anything. We look at how much milk the cows give and whether they stay healthy. If nothing is wrong, we will take a step down.”

Always to another field

Leendert van Staalduijnen has already reduced the protein content in his feed: he is now at 146 grams of crude protein. Much lower is not possible without consequences for the cow or milk production. In his plans for more grazing, Van Staalduijnen will also have to take into account the consequences of the changed cow diet. When the cows are in the barn, he knows exactly what they are eating. In the meadow, he depends on the grass growth and how nutritious it is: Van Staalduijnen will have to constantly balance the feed if he wants to continue giving little concentrate.

At the kitchen table, the discussion about the grazing plan continues. Niek Konijn, Van Staalduijnen’s supervisor and coach from the network, draws the curtains, rolls out a portable screen and puts a beamer on the table. They continue talking on the basis of aerial photos of plots and the ‘Kringloopwijzer’ – a kind of annual report of the dairy farm, filled with spreadsheets full of nutritional values ​​of grass, concentrates, how much the cows ate, how much milk they produced and how much protein they contained.

The trick is to let the cows graze in a different field each time. The farmer has to reclassify it for this

Van Staalduijnen now sometimes allows his cows to walk on the same plot for several days. After a few days, the nutritious grass is gone and the cows produce less milk. De Beer calls this the ‘last day syndrome’. “The trick is to graze in a different field every day. Then you never have a last day, but always a first.” To do this, Van Staalduijnen has to rearrange his plots. They are now of different sizes, but must be the same size, so that the cows eat about the same amount of grass every day.

Going outside for more hours is also possible, De Beer thinks. But then Van Staalduijnen has to start grazing earlier in the season. The grass on the meadows must therefore be ready for this. This year it didn’t work: the soil was still too wet to fertilize in early spring.

Farming this way is not easy, Migchels of WUR admits. But he is convinced that the lessons learned in the network can be applied to almost all dairy farmers. “Every farmer will have to reduce nitrogen emissions, including the livestock farmer who has received slightly fewer talents from our dear lord.” A quarter less nitrogen emissions is quite possible, says Migchels: “There is still a lot to be gained from concentrates.”

Emissions and nitrogen administration

There is one problem: how do you convince politicians and the courts that emissions have actually been reduced? Measurements are taken at Van Staalduijnen’s farm by WUR, because the scientists in the network want to know what the management measures yield. That only happens in the stables, but that’s where the cows spend most of their time. Its emissions are more than 30 percent lower than in a traditional cowshed, according to those measurements.

But the measuring equipment is expensive and it is not possible to measure in every house. Migchels advocates clear nitrogen administration. “What is the input and output of nitrogen on the farm? What exactly was fed?” This makes it possible to keep track of how much ammonia is emitted. “We are thinking of a kind of green accountant who can check the accounts. If he gives it a blow, the enforcer knows: this is correct.”

If I do everything I can to reduce my emissions, can the government force me to stop?

Van Staalduijnen hopes that the management measures are enough to keep his company. “If I do everything I can to reduce my emissions, can the government force me to stop?” Should Van Staalduijnen threaten to be bought out by the government, Migchels is prepared to help him in court. “Then I am an activist researcher. We can show the judge all the sums.”

This year, Migchels wants to set up a system with the network that sufficiently substantiates the effect of the management measures to withstand the strict legal tests. Only then can it play a role in, for example, licensing and policy to reduce nitrogen emissions. He has no doubts about the results of the measures. “It’s possible. It’s low-hanging fruit.”