1) Monteny Milieu Advies, August 2021: Model-based assessment of the reduction potential for NH3-emission of the innovative solid floor KRAIBURG – profiKURA 3D
2) source: www.ammoniak.ch/massnahmen/rindvieh
Less ammonia and better air in cow barns: Reducing emissions with the correct barn flooring
Fachwissen
Among various other industries, livestock husbandry is also a source of airborne emissions. Ammonia (NH3), in particular, plays a key role here. Ammonia emissions from barns account for the second largest share of all NH3 emissions in agriculture after slurry spreading and storage. Reducing ammonia losses not only means active environmental protection but also ensures the utilization of the valuable nutrient "nitrogen". Neither plants nor animals can survive without nitrogen. The more nitrogen is lost in the natural cycle of materials, the more it must be supplied from other, often mineral, sources through fertilization.
Under the NEC Directive, EU Member States are obliged to reduce national air pollutant emissions by an agreed percentage. Germany, for example, has committed itself to reducing ammonia emissions by 29% by 2030 compared to 2005, while Austria aims to reduce them by 12%. Switzerland has set itself the target of reducing its annual ammonia emissions by almost 50% by 2023 compared to 2015. This corresponds to 23,000 metric tons of ammonia each year. Achieving these targets requires appropriate emission-reducing measures.
At present, cattle farmers are only obliged to implement emission-reducing measures in or at their barns if their herds exceed a certain size or if they are located in particularly ecologically sensitive areas. However, their implementation is already being promoting at government level through investment promotion programs – in Germany primarily through the federal government's Agricultural Investment Promotion Program (AFP) guidelines, although the German federal states can set different priorities. As a rule, specific measures are stipulated in the federal state specifications. They often include emission-reducing rubber flooring for walking areas. The KTBL publication "Eligible techniques for reducing emissions in livestock buildings" (2022) provides an overview of suitable measures. In Austria, the Austrian Federal Ministry of Agriculture, Forestry, Regions and Tourism (BML) publishes detailed promotion fact sheets. In Switzerland, the "National Ammonia Platform" provides a general overview of ammonia reduction in the country.
How is ammonia produced?
When urine containing urea comes into contact with the enzyme urease found in animal feces, it undergoes a specific chemical reaction over time and under specific ambient conditions, resulting in the production of ammonia and carbon dioxide.
How much ammonia is produced depends on various factors:
-
The size of the polluted area - "emitting area"
-
The time that is available for the reaction
-
Further factors, such as pH value, temperature, air velocity, nitrogen concentration etc.
In barns, feces and urine are mainly combined on walking areas and in the slurry pit. The best opportunities to exert influence can, therefore, be found here.
In traditional tying stalls, the polluted and thus emitting area was relatively small compared to state-of-the-art free stall barns. However, to achieve a contemporary level of animal welfare, free stall barns with a greater amount of space for the animals have become the widely accepted norm. Since intensive and nature-friendly, pasture-based grazing is not possible everywhere. A well-managed pasture provides natural husbandry in terms of animal welfare and, at the same time, low NH3 emissions, as animals defecate and urinate at different times and usually in different places.
For state-of-the-art free stall barns, it means attempting to replicate and optimizing these impacts as best possible with the aid of structural-technical solutions. For example, the percentage of "emitting" areas can be reduced through the use of elevated feed stalls and well-structured exercise yards. A slope in all or in parts of the walking area promote the often-described rapid separation of feces and urine.
Basic principles of ammonia reduction in barns
The best way to reduce emissions in barns is to ensure clean, dry surfaces where feces and urine are separated as quickly as possible. This applies to all floors and ground areas inside and outside the building. When it comes to walking areas, regular manure removal through a manure removal technique adapted to the floor is absolutely essential to ensure adequate cleaning. Generally speaking, a scraper frequency of at least every 2 hours is recommended.
Elevated feed stalls can also reduce the size of the emitting area, provided a feeding place divider is installed at least at every second feeding place. As such, the animals soil the feeding place less and the scraper frequency can be increased, since the scraper does not disturb the animals during feed intake. The cows can feed undisturbed, while remaining clean and dry. All this has a positive impact on feeding behavior, feed intake and hoof health. We recommend our LENTA rubber mat to ensure cows stand at the feeding place in a hoof-friendly and pleasantly soft way. (View product)
Since ammonia production is also influenced by temperature and air velocity at the surface, optimized aeration not only reduces heat stress in animals but also has positive impacts on emissions.
Storage tanks containing a urine-feces mixture, including slurry pits, should be kept covered as much as possible.
Eligible techniques for reducing emissions
The KTBL publication "Eligible techniques for reducing emissions in livestock buildings" (2022) summarizes the current state of knowledge on emission-reducing technologies in Germany and provides an overview of suitable measures. This positive list is used by many funding agencies and is widely accepted as verification. In addition, there are also positive lists available in Austria and Switzerland.
The following KRAIBURG product solutions can be assigned to the categories described therein. All or some of the products listed are already approved in other countries, such as in Scandinavia and the UK:
1. Paved floor with cross slope and urine-collecting gutter
profiKURA P on concreted slope or profiKURA 3D
The paved floor has a 3% cross slope toward the urine-collecting gutter and allows liquids to drain quickly. The slope can be concreted during construction and covered with rubber flooring. The corundum surface of the profiKURA P walking alley mat ensures high slip resistance, which is especially necessary for walking areas with a cross slope. Concrete floors with inclinations greater than 2% can turn slippery very quickly.
When it comes to constructing new barns or converting existing ones, profiKURA 3D rubber flooring is an ideal choice for greater flexibility. It has a 3% slope integrated directly into the mat – elaborate, slope concreting is no longer required.
The surface should be scraped clean at least every 2 hours with a manure removal device. The scraper usually only needs to be adapted to the slope once. The manure removal scraper should have the capacity to clean the urine-collecting gutter at the same time, unless the gutter is flushed.
According to the KTBL publication, this type of floor has an ammonia reduction potential of between 20 – 38%. Compared to slatted floors in a standard Dutch dairy barn, an expert report certifies that profiKURA 3D has an emission reduction potential of up to 44% 1) .
In contrast to straight, paved floors or grooved floors, rapid drainage of urine into the urine-collecting gutter on inclined floors helps prevent "slurry ponding" when removing manure. This can help to further reduce the exposure of hooves to bacteria and moisture.
The urine-collecting gutter offers greater system safety. However, it does not directly impact the reduction in emissions, provided that the liquid can drain off sufficiently. It is very rare that high-volume urine-collecting gutters can be retrofitted in existing barns. In covered walking areas, a higher frequency of manure removal and a sufficiently deep scraper guide channel can prevent the formation of urine puddles in many cases. 2)
2. Paved grooved floor with profile
profiDRAIN
The paved floor consists of a profiled surface with integrated longitudinal grooves. The urine drains off into the longitudinal grooves and is removed with the aid of a "comb scraper", whose scraper lip must be adapted to the shape of the grooves. According to the KTBL publication, this type of floor has an ammonia reduction potential of between 31 – 35%.
The curved surface of the profiDRAIN mat with an approx. 6% slope toward the drain channel allows liquids to drain quickly and reliably into the drain channels. The optiGrip surface offers excellent slip resistance. The drain channel mat is suitable for new constructions and renovation projects.
3. Rubber flooring with convex curvature toward the slit in perforated floors
KURA SB
The quick and reliable drainage of urine should also be aimed for in slatted floors. Ideally, the opening to the slurry pit should be reduced by means of smaller slats. The KURA SB rubber flooring drains liquids very quickly thanks to the approx. 5% slope toward the slit on both sides. The feces remain on the surface and are regularly removed by a well-adjusted manure removal scraper with flexible scraper blades. According to the KTBL publication, this type of floor has an ammonia reduction potential of approx. 38%. Based on our practical experience, a well-adjusted manure removal robot can be employed. The advantage of this is that crossing passages in the barn between walking alley axes can also be cleaned with the robot, eliminating the task of manual cleaning for the farmer. The studs on the lower side allow for a softer, more natural walking experience due to flexible deformation of the mat under load. Together with the profiled surface structure of the mat, they guarantee greater slip resistance for both animal and human. The rubber mats are suitable for new constructions and renovation projects and can be installed directly on the existing slatted floor.
The KTBL publication „Förderfähige Techniken zur Emissionsminderung in Stallbauten“ ("Eligible techniques for reducing emissions in livestock buildings") (2022) summarizes the current state of knowledge on emission-reducing technologies. This positive list is used by many funding agencies for the promotion of investments and is widely accepted as verification.
5. Reducing emissions – animal welfare and environmental protection go hand in hand
Emission-reducing walking areas are not only positive from an environmental perspective, they also help boost animal welfare. An emission-reducing rubber mat in the walking area leads to the quick drainage of liquids and thus, in combination with a well-adapted manure removal technique, also to drier and cleaner walking areas. These floors, therefore, support good hoof health thanks to drier hooves with a lower bacterial load. In addition, rubber flooring is soft and animal-friendly, replicating natural grasslands better than hard concrete. Due to sinking in of the hooves and an optimized surface, good rubber mats provide the necessary grip for high slip resistance and the sure-footedness of both animal and human.
A cow that feels relaxed and can move in a safe manner and, in the truest sense of the words, "stands on healthy legs" has been proven to deliver a more consistent milk yield. Owners benefit from the greater productivity of their herds.
Summary
Emission-reducing walking areas simultaneously meet the demands for more environmental protection and animal welfare. Increased space for activity in relation to animal welfare means more polluted, emitting areas. An emission-reducing floor produces fewer emissions across the same area and also offers other benefits in terms of animal friendliness and welfare. A conflict of goals between animal welfare and emission reduction becomes a harmony of goals – since they now go "hand in hand". By combining various emission-reducing measures when constructing new barns or converting existing ones, a lot can be done for animals and the environment. Elevated feed stalls, emission-reducing flooring and correct structuring of the exercise yard with free stalls can reduce the additional emissions caused by providing an exercise yard. These measures have been tried and tested and are ready for practical application. They have a positive impact on animal welfare, hoof health and thus also on productivity. Government subsidies fully or partially offset additional costs for farmers and ensure a quick return on investments.
Watch our solutions in video
Our consultants explain our solution and show you the products – practical and live in the barn!
Stay up to date with our guidance newsletter!
Subscribe to get regular practical tips and advice as well as the latest news from KRAIBURG.