Video: 'Cow toilet splendid opportunity to easily reduce emissions'
Jan-Willem Tijken, dairy farmer in Zelhem, Gelderland, is clear: "The CowToilet offers many opportunities for dairy farmers. It works very practically, requires little maintenance and time, low financial investment and most importantly the nitrogen emission from the dairy is 41 per cent lower."
20-2-2024 | 10 min
The CowToilet, or cow toilet, is an innovative system developed to collect urine from cows and separate it from solid manure. When urine and solid manure come together, there is ammonia formation and thus nitrogen is released. Separation is done very simply in the concentrate box. "The cow walks in and gets her portion of concentrate feed. The toilet bowl behind the cow moves up and down under the cow's tail to trigger the urination reflex. The urine is collected and the cow walks forward out of the stall again. After all, a cow never urinates and defecates at the same time."
10 visits per day
Jan-Willem Tijken (43) looks at the dashboard on the computer: "The monthly average for my 50 cows is 10 visits per day with 7.3 urination. The CowToilet captures 15-16 litres per cow per day. I am super satisfied with it." On his mobile and PC, he can track everything. In summer, the number of visits drops because of grazing.
Intensive dairy farm
Family Tijken, Jan-Willem, Femke and four children, keeps 55 dairy cows, 20 young cattle and 35 bulls on 32 hectares of land. "So we are an intensive farm and have to dispose of about 400 cubic metres of manure every year. We use the urine instead of fertiliser. That opens up opportunities for our business," Jan-Willem explains. Besides being a dairy farmer, Jan-Willem is a practical teacher for mbo green at Zone.college. "I used to work at pilot farm De Marke and was used to a lot of contacts. The schoolchildren come here on the farm to learn practice. I think it's a great combination," says Jan-Willem enthusiastically.
Two manure streams
In January 2019, Hanskamp posted a video about the CowToilet. "In March, Henk called Hanskamp to ask if we wanted to test the CowToilet. I did see possibilities of separating the manure and was happy to cooperate," Jan-Willem looks back.
At the back of the cubicle shed, Hanskamp built the first toilet. "It looks like a concentrate box. In the first toilet, cows walked in forward and out backward. The cows visited the toilet 400 times a day. We stored the urine in 1,000-litre drums."
The aim, of course, was to collect as much pee as possible. "A walk-through station was better. At the front of the barn, Hanskamp installed two CowToilets in early 2019. The number of visits immediately increased from 400 to 600 per day. The cow feels comfortable, you can see that. It is equivalent to a visit to a concentrate box. Now she can pee at the same time." The dairy farmer cannot detect differences in quantities of urine between different breeds of cows, rations or stage of lactation. "Some cows go 20 times a day and others less. There is no line in it. The barn is drier and the cows have fewer claw problems."
Practical toilet
Jan-Willem is satisfied with the maintenance. Every 14 days, he sprays off the plastic mesh in the toilet bowl. "Other than that, I don't have any work on it. Just a spray clean when visitors come," he laughs. In December 2023 was the first maintenance. Only a few hoses had to be replaced. "All in all, using the CowToilet is little different from a conventional concentrate box. That is also the strength of this system. Without much work or rebuilding, the toilet is easy to install in existing stables."
Payback period
Current fertiliser prices are not so shocking anymore and more stable around 35-40 euros per tonne. The cost of manure disposal, however, is rising sharply and is already 30-40 euros per cubic metre. Hanskamp says that based on the amount of manure to be removed, the CowToilet can now be earned back in 5-8 years. An additional benefit when investing in a CowToilet, is that a new concentrate feeding system is added and individual concentrate feeding can be optimised.
Alternative to artificial fertiliser
Tijken installed a 175 cubic metre silo for urine storage. "This can just about hold the quantity from late August to May," says the dairy farmer. The nitrogen-rich urine can be used as an alternative to fertiliser. "We use it after the first cut of grass in early May. At the end of April it is still colder and I am afraid of volatilisation or leaching because of its quick availability. We have to buy a small amount of fertiliser anyway so we use it early in the season."
The dairy farmer used the urine during different weather conditions. "We had very dry summers where we had to watch out for burning and we irrigated immediately. In 2021, we had more rain and could apply when it was convenient." At the low dosage of 5 cubic metres per hectare, Jan-Willem added water. "Fertilising with the trench counter goes well. It's a bit of fitting and measuring how to properly distribute the small gift at appropriate rates."
Rav measurements
Tijken has the test barn status whose emission is set at 7 kg of nitrogen per cow per year. The Rav measurements have now taken place. "That has quite a lot to do. Measuring in all weather conditions and seasons. Before measuring, the cows had to be in the barn for four days so that the concentrate feed is distributed properly over the 24 hours. The wind had to come from the South West and there is nothing as changeable as the weather." Reporting for final emissions is ongoing and has yet to be determined. Until then, the CowToilet reckons with 8.4 kg of nitrogen per cow.
After a year of measurement by Wageningen Livestock Research, emissions of total nitrogen, ammonia, nitrous oxide and nitrogen gas, including estimated loss during urine storage, were respectively 38, 33, 18 and 43 per cent lower compared to a reference barn.
Working together on sustainability
"From horticulture, there is increasing demand for sustainable manure. What could be better than having local cow farmers supply urine to market gardeners and nurseries? The solutions are there for the taking," says Jan-Willem Tijken.
Hanskamp has started urinebank.nl. It is the place where supply and demand of cow urine are brought together. Sales to, for example, horticulturists for which high manure disposal costs are avoided, less purchase of fertiliser. "Beautiful challenges. Many politicians and officials have already come here to see it. They are all enthusiastic but the political decisions are lacking. That is a pity. Industry and farmers are sticking their necks out with innovations but we are running into closed doors," Jan-Willem Tijken concludes.
Hoe werkt het CowToilet in de praktijk
