Urea and Amino Acid Supplementation of Swine Diets

Abstract

Three metabolism and four feed trials were conducted to investigate the utilization of urea and the effect of amino acid supplementation using a basal corn-soybean meal diet. The results, although not conclusive, indicate that some urea (1 to 2%) can be used by the growing pigs. However, the diet must supply the essential amino acids, or they must be added if there is to be a positive response. An amino acid imbalance was observed when 0.5% lysine was added to a diet containing 2% urea. It was overcome by supplementing the diet with tryptophan and methionine. When imbalances were observed, food intake was depressed. Blood urea levels were higher when pigs were fed diets containing urea. The increase of blood urea levels was directly related to the dietary level of urea and inversely related to the length of time pigs were fed urea.