Organic acids in diets for entire male pigs

The aim of this study was to investigate the effect of organic acids in diets for entire male pigs on growth performance, composition of microbiota in the gastrointestinal tract (GIT), on concentration of skatole and indole in digesta, plasma and adipose tissue, and concentration of volatile fatty acids (VFA) in digesta. Restrictively-fed pigs (n = 60) (28 and 113 kg initial and final BW, respectively) were used. The dietary treatments consisted of a basal diet and the basal diet added either 1.0% formic acid, 0.85% benzoic acid, 0.85% sorbic acid, 1.2% fat coated Ca-butyrate or 1.5% fat and inulin coated Ca-butyrate. All levels of organic acids corresponded to 0.85% of pure acid. Digesta samples for microbiological examinations were taken from the proximal jejunum, colon descendens, and rectum. Digesta samples for skatole, indole and VFA analyses were taken from colon descendens. The results showed that the addition of organic acids to diets had no effect on daily weight gain or feed intake, but formic, benzoic and sorbic acid tended to improve FCR of pigs compared with the control pigs. Organic acid supplementation did not affect levels of skatole, indole, or VFA in the digesta or levels of skatole or indole in adipose tissue compared with the control. Plasma skatole levels were reduced in pigs fed diets containing formic and benzoic acid compared with the control pigs. Pigs fed organic acids had lower levels of coliforms, enterococci and lactic acid producing bacteria in all three sampling sites of the GIT. Supplementing diets with organic acids did not affect levels of skatole in digesta or adipose tissue of entire male pigs.