Short Description of the Technology

In intensive livestock farming systems animals are often kept in a barn with a concrete floor. The traditional floor system in fattening pig barns is a slatted floor. This way manure that is dropped from the animals, falls through the slats in the manure pit underneath. The manure that is collected here is stored for a longer period of time until the manure pit is full or manure is needed for fertilization purposes. Within the ECONUTRI project, ILVO investigates the effect of daily removal of manure from the manure pit of a fattening pig compartment. This is done by draining of the pit into a sewerage system using a pump. This is a low-cost and low-maintenance system, compared to similar systems that use flushing or scraping to empty the manure pit. The manure on the floor and in the manure pit are the source of ammonia (NH₃) and greenhouse gas (GHG) emissions.  Removing the manure on a frequent basis from the manure pit can decrease the levels of GHG and NH₃ production in the pit and can result in increased animal health.

In dairy a similar slatted floor as is found in fattening pig barns can be present in the walkways of the dairy barn. Some barns, however, have full concrete floors without slats. In both cases, the floor needs to be cleaned several times a day for hygienic purposes. This is done with manure scrapers or robots that automatically remove manure from barn floors. Within ECONUTRI, ATB is investigating the effect of manure removal frequency from dairy barn floors on NH₃ and GHG emissions. By minimizing the time manure remains on the barn floor, it limits the exposure of manure and urine to the atmosphere and also limits the breakdown of organic matter, thereby improving air quality and environmental sustainability.

Innovative Features

Traditionally, manure removal from the barn or floor is done for hygienic or practical reasons and not for reducing emissions. Frequent manure removal in pig and dairy barns is innovative for emission reduction because it directly addresses the primary sources of methane (CH₄) and NH₃ emissions from manure without the need for manure treatments or (chemical) additives. This makes frequent manure removal a relatively simple yet highly effective innovation for reducing emissions in livestock farms. There is not much research conducted on this technology and in the Econutri project this technology is tested at commercial barns.

Type of Contribution (e.g., reduction of nutrient losses, greenhouse gas emissions, etc.)

Frequent manure removal contributes to lower ammonia and greenhouse gas emissions by reducing the exposure of manure and urine contaminated surfaces to the adjacent atmosphere:

• Reduced methane emissions – Methane is produced when manure decomposes anaerobically (without oxygen). By frequently removing manure, particularly manure from storage pits, the duration of anaerobic decomposition is minimized, thereby cutting methane production.
• Limited nitrous oxide (N₂O) emissions – Nitrous oxide is produced when nitrogen in manure undergoes microbial processes like nitrification and denitrification. Manure stored for long periods in pits creates oxygen-poor environments, ideal for denitrification and N₂O production. Regular manure removal limits microbial activities and anaerobic conditions, reducing N₂O emissions.
• Lower ammonia levels – Ammonia forms when urine and feces mix, and its volatilization increases with prolonged exposure. Frequent removal prevents ammonia buildup, improving air quality for both animals and workers.

In addition, this technology will help conserve the nutrients in the slurry by reducing losses.

Benefits for farmers, the industry, and the environment

Automated frequent manure removal from the barn benefits the farmer through better animal health and productivity as reduced exposure to harmful gases improves respiratory conditions for livestock, leading to better growth rates and/or milk production. This way, it will benefit the farmers economically. By mechanically removing manure more often, the reliance on additives or acidifiers to reduce emissions is minimized. At the same time, it will help conserve the nutrients in the manure and the application of that nutrient-rich manure to soil will reduce the synthetic fertilizer input.

Freshly collected manure will also benefit the industry and the environment, as fresh manure can be processed more efficiently in anaerobic digesters or composting systems, enhancing nutrient recovery and bioenergy potential. At the same time the lowered emissions from the barn will help in biodiversity conservation and reduce environmental pollution and climate change.