Reduction of ammonia and odour emissions from pig slurry under slats using oil and foam layers.

In Europe, new legislation on environmental protection requires reductions in emissions of ammonia and odour from animal production. Animal housing is identified as one of the biggest ammonia emission sources in pig production, but abatement techniques for animal houses often require high initial cost. The aims of this study were to investigate the use of layers of oil and foam on slurry under slats. It was found that relatively low-cost, used frying oil (mainly rapeseed oil) could reduce ammonia and odour emissions by about 50% in weaner accommodation. The cost for this technique was Pound Sterling 2.60 per pig place per year. Foam showed poor ammonia abatement potential. The oil was biodegradable, so increasing methane emissions from stored pig slurry by about 60%.