Effects of Dietary Protein Content and Using Sugar Beet Pulp or Benzoic Acid Supplementations on the Nitrogen Excretion of Fattening Pigs and its Composition

Abstract

In this trial, the effects of different nutritional treatments on the N balance parameters of fattening pigs in the 55–65 kg live weight category were evaluated. The following diets were used: control diet (C) and low-protein (LP) diet with 2% crude protein reduction, with and without 10% sugar beet pulp (S) or 0.5% benzoic acid supplementation. Six pigs per treatment with similar live weight were used, and in the context of the balance trial, the daily N intake, fecal and urinary N excretion and the pH of urine were measured. From the data N digestibility, the TAN % and N retention were calculated. Feeding LP diets reduced the fecal, urinary and total N excretion and also the pH of urine significantly compared with the control diet. Sugar beet pulp significantly increased the fecal N excretion and urinary pH, and it also reduced significantly N digestibility and the TAN ratio. Benzoic acid failed to reduce urinary pH. The measured N excretion, retention and TAN excretion values were more favorable than those that can be found in the different guidelines or those used in the Hungarian ammonia emission inventory.