Careful nutrient management planning is needed with increased intensity of the pork industry and with increased public concerns regarding nutrient excretion or odour emissions. Over-supplementation of diets with nutrients to ensure maximum pig performance resulted in excessive amounts of nutrients excreted in faeces and urine (Bake and Zublena, 1985). Successful nutrient management is key for sustainable pork production. Two principal nutrients of concern are nitrogen and phosphorus. Nitropgen is concern because of its impact on the inside and outside of the barn environment. Swine production has been recognized as a major source of ammonia, which is a noxious gas for humans and animals and contributes to bad odour and acidification of the environment. The main component of ammonia emission originates drom urea in urine, Fecal nitrogen is less volaltile than urinary nitrogen, because fecal nitrogen is bound with other proteins or compounds. Phosphorus is excreted in urine and faeces, and could have a major impact on the environment and the economy if not managed properly (Cromwell et al. 1993; Liu et al. 1998, NRC. 1998)