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Feed additives such as probiotics, prebiotics, Zn and Cu, non-starch polysaccharide degrading enzymes, and phytogenic feed additives can stabilize the gut function in piglets. In many cases, organic short and medium chain fatty acids (MCFA) are used because by their impact on the digestive processes and the intestinal microbiota. It can be hypothesized that the combination of short chain fatty acids (SCFA) and MCFA might be potentially increasing the efficacy of the gastrointestinal functions of young piglets.
The objective of the present work was, to study changes in the gastrointestinal microbiota in weaned piglets fed diets with different combinations of organic acids (OA) and MCFA. A total of ninety-six 25-d-old castrated males (Duroc × Pietrain) (2 piglets/pen) were weaned and randomly assigned to 4 diets, without additive (control), with organic acids (OA; fumaric and lactic acid), with medium chain fatty acids (MCFA; caprylic and capric acid), and a combination of OA and MCFA, to assess changes in the gastrointestinal microbiota with 12 pens per diet.
The fumaric acid concentration was below the detection limit in the upper small intestine whereas the concentration of lactic acid in the digesta was not affected by the treatments. The added MCFA was recovered in the MCFA treated groups in the stomach, but the concentrations declined in the upper small intestine. Concentration of short chain fatty acids was reduced in the colon digesta in piglets fed diets with OA compared with those fed the non-supplemented diets (P = 0.029). The MCFA resulted in a pH reduction of the digesta, likely because of the effect on bacterial acid production. The addition of OA increased cell counts of Bacteroides-Porphyromonas-Prevotella group and clostridial clusters XIVa, I, and IV in the stomach, the clostridial cluster XIVa in the jejunum, and Bacteroides-Porphyromonas-Prevotella in the ileum and reduced counts of Streptococcus spp. in the colon (P < 0.05). The MCFA induced only minor changes in the gastrointestinal microbiota but increased cell counts for the Escherichia-Hafnia-Shigella group in the jejunum and the clostridial cluster XIVa in the colon digesta (P < 0.05). In the colon of piglets fed diets with OA, reduced mean cell counts of STb (est-II) positive Escherichia coli were found. In conclusion, the data obtained from the study showed that OA and MCFA had an impact on the composition of the intestinal microbiota and the intraluminal metabolites.
Based on the present observations, the reduction of pathogenic bacteria in the intestinal tract by OA, as well as the effect of MCFA on the pH in the stomach and small intestine seems to be relevant. Both could be useful to maintain the intestinal health of piglets in the period after weaning.
Zentek, J., Ferrara, F., Pieper, R., Tedin, L., Meyer, W. and Vahjen, W. 2013. Effects of dietary combinations of organic acids and medium chain fatty acids on the gastrointestinal microbial ecology and bacterial metabolites in the digestive tract of weaning piglets. J. Anim. Sci. 91:3200–3210. Doi:10.2527/jas2012-5673
