Good drainage is a key component of controlling ammonia emissions in livestock operations. The amount of ammonia emitted by a livestock operation depends on a range of factors including room temperature, ventilation/air movement, feed composition, and floor construction/drainage. Lowering ammonia emissions can positively impact animal health, employee health, and environmental footprint. Focusing on incorporating drainage design into a new build or during facility upgrades is a one-time investment that can improve animal productivity, employee retention, and environmental stewardship for the life of the operation.
How Drainage Affects Ammonia Emissions
Studies have shown that waste management, through proper drainage, can affect the overall emissions from livestock operations. In the 2016 study “Floor slat openings impact ammonia and greenhouse gas emissions associated with group-housed gestating sows” researchers found that increasing floor drainage by 12.5% resulted in a 19% reduction in NH3 emissions. Once urine and feces are removed from the floor through advanced drainage techniques and floor scraping they can be manipulated to further reduce emissions. This can be achieved by controlling the temperature or pH of the slurry. Please see the article Environmental and management techniques to reduce ammonia emissions for housed cattle for more information.
Drainage and Animal Welfare
Increased drainage can be achieved by reducing the floor space allotted for each animal while increasing the percentage of the floor that is slotted. However, it has been observed that this combination of reduced living area and increased slotted floor harms animal health and productivity. This has led to recommendations to provide animals with the greatest floor space possible while limiting slotted floors. Larger pens with solid floors can therefore promote animal health, increasing productivity per animal. But this arrangement can also increase ammonia emissions. Increased emissions can lead to greater pressure on ventilation and heating or cooling systems. How then can we increase drainage area while reducing ammonia emissions and associated air exchange requirements?
Sloped Floors and Centralized Drains
A centralized trench-style drain in walking areas is a natural fit for state-of-the-art operations that want to replicate natural pasture-based grazing in indoor operations while managing waste. A Slot Drain System is durable, flush fitting, easy to clean, and can provide flow rates of up to 27 GPM per foot of drain. Sloping the floor towards the slot drain at a rate of anywhere from 0.5% to 3% can provide positive drainage towards the slot drain separating solid from liquid waste and controlling ammonia emissions in livestock operations through drainage. Greater floor slopes can reduce ammonia emissions by more quickly diverting liquid waste towards the slurry pit. However, those slopes can put greater stress on the animal. This can be alleviated through the use of rubber floor coverings which provide anti-fatigue and slip-resistant properties to sloping floors.
Choosing a Drainage System for Livestock Operations
Drains themselves need to be resistant to the corrosive effects of ammonia as well as other chemical agents that can be produced or encountered in the practice of animal husbandry.
Drains manufactured with stainless steel have an extremely high resistance to corrosion. This is because stainless steel is an alloy with a minimum chromium content of 10.5%. This chromium reacts with oxygen to form a protective chromium oxide film that gives stainless steel its corrosion resistant properties.
Drains need to be able to stand up to abuse. They form part of the floor and as such need to be engineered with proper weight class ratings to avoid bending or cracking. If a drain bends or cracks under the weight of animals or machinery it can become hazardous to animal health and may need to be repaired or replaced. A drain that does not maintain its functionality can end up costing more in the long run in repairs or sanitary upgrades.
Slot Drain Systems offers a range of drains built from T304 and T316 Stainless Steel. Stainless Steel Slot Drain Systems are load class rated, corrosion resistant flush fitting, and can be engineered to your specifications. There are many moving parts in a modern livestock operation and it can be easy to overlook drainage. Our team of experts can help you with custom solutions and product planning. Whether you are building a new operation, or planning sanitary upgrades to an existing operation, our team has the capacity and the experience to guide you through every step. Slot Drain Systems are an ideal solution for reducing ammonia emissions and increasing sanitation and safety through drainage in a modern livestock operation.
