The main sources of ammonia in a pig-housing unit are the slurry pit and urine puddles. Less nitrogen is excreted when protein in the diet is decreased, while increasing fermented carbohydrates like sugar-beet pulp increases nitrogen excretion in the feces and less in the urine. Fecal nitrogen is much safer as it takes longer to decompose due to its higher stability. Ammonia emissions were measured from slurry samples produced by pigs that had different diet compositions fed to them. Two sets of model calculations were compared to the results. The most significant input parameter was slurry pH. The concentration levels were not predicted well by either model but the fluctuation in emissions could be simulated by both.
Simulating Ammonia Emissions from Slurry Pits (full article)
