Effect of salts and organic acids on metabolite production and microbial parameters of piglets' digestive tract

Twenty four pigs, weaned on the 28th day of life were divided into 4 groups of 6 animals each and placed in pens of 2 animals each. The pigs were fed ad libitum a mash standard starter diet. The control group was given feed without any acidifier preparation and the experimental groups were fed the same feed to which 10 g/kg of sodium formate, benzoic acid or fumaric acid was added. Compared to the control group, sodium formate increased significantly the concentration of formic and butyric acids in the duodenum and lactic acid in the ileum and decreased the concentration of formic acid in the caecum (P < 0.05). Moreover, significantly lower numbers of lactic acid bacteria in the caecum were observed. Compared to the control group, the addition of benzoic acid increased significantly the number of Clostridium perfringens in the caecal digesta and in the faeces, the concentrations of lactic acid in the duodenum and of butyric acid in the ileum, and decreased the formic acid concentration in the caecum. In the group fed the diet supplemented with fumaric acid, no difference in acid concentrations and in the number of bacteria in the digesta and faeces was found. Preparations used in investigations could affect the composition of microflora and counts as well as the activity of bacteria (organic acids and ammonia production) in individual segments of the digestive tract.