THE METABOLIC FECAL NITROGEN EXCRETION OF THE PIG AS INFLUENCED BY THE TYPE OF FIBRE IN THE RATION AND BY BODY WEIGHT

Abstract

Nitrogen balance studies were carried out on growing pigs (15 to 60 kg. body weight) using protein-low rations (approximately 0.3 per cent) to study the influence of body weight and type of fibre in the ration upon metabolic fecal and endogenous urinary nitrogen (N). The types and amounts of fibre used were: pure wood cellulose (Solka-Floc), 7 and 14 per cent of the ration; methocel, 7 and 14 per cent of the ration; and oat hulls, 14 and 28 per cent of the ration.Type and amount of fibre significantly affected the metabolic fecal N excretion of the pig, whether expressed on the basis of dry matter (D.M.) intake or fecal D.M. output. Wood cellulose (Solka-Floc) caused the greatest, and methocel the least, fecal N excretion per unit of D.M. intake. Oat hulls were intermediate.Fecal N excretion varied inversely with the 0.3 power of body weight between the body weights of approximately 15 and 60 kg.Endogenous urinary N in one experiment varied with approximately the 1.0 power of body weight, and in a second experiment with the 0.2 power of body weight. It was not possible in these experiments to determine the factors that influenced endogenous urinary N excretion.