Effect of Enzyme Inhibitors on Ammonia Emissions in Broiler Houses

As the livestock/poultry industry has grown, so have the concerns about the air and water quality, conservation and environmental management aspects of these industries. Poultry operations are rapidly expanding in Kentucky and are the second largest contributor to farm income in the state ($ 505.9 million)1. There is increased concern related to ammonia emissions from the poultry industry as it affects the environment and human health. Lawsuits are pending between Kentucky poultry producers, their integrator and environmental groups over ammonia emissions. Various abatement methods, including dietary manipulation, chemical amendment of litter, and improvement in ventilation rates have been used to control ammonia concentrations from livestock facilities. Alternative strategies include reduction of ammonia emissions by arresting nitrogen in the litter. This can be achieved by blocking the enzyme activity in the enzymatic degradation of uric acid to ammonia. However, it is unclear whether strategies to reduce concentration have much impact on total emissions from a facility. Indeed, our current work (www.bae.uky.edu/IFAFS) suggests that ventilation rate has a substantially larger impact than concentration, on ammonia emissions (the product of ventilation x concentration). The immediate goal of the proposed research is to decrease ammonia emissions by inhibiting the activity of the enzyme uricase by using minerals such as zinc and copper sulfate; and urease by using certain urease inhibitors. We will accomplish this by: 1) accurately measuring the ammonia over one year (or five flocks) from pens treated with urease inhibitor (applied directly on litter) and zinc and/or copper sulfate (introduced in the diet); 2) measuring the nitrogen content in the broiler litter and feed; 3) usage of zinc and/or copper sulfate as feed additives and their role in reducing ammonia emissions; and 4) measuring zinc and copper in the broiler litter. We expect the use of enzyme inhibitors and minerals to constitute promising approaches to reduce ammonia emissions from broiler houses. By using these techniques the poultry producers will benefit from reduced ammonia emissions, improved environment in and around the facility, reduced ventilation rates thus reducing the expenditure on energy and, improved bird health and overall production. More detailed information on the use of minerals to reduce ammonia emissions from broilers is needed. The use of zinc and/or copper sulfate as feed additives may result in accumulation of heavy metals in the litter, and thus problems in disposing litter to the fields. This study will enhance the sustainability of US poultry producers and help reduce environmental impacts.