Novel opportunities for promoting growth in productive animals by nutritional means have emerged after the ban of antibiotics as feed additives in the European Union. Regarding the immune system of swine and despite the published reports on piglets and sows, data on the dietary effects of probiotic, prebiotic and organic acid on fattening pigs are very scarce in the literature.
A total of 160 pigs were used during the fattening period to evaluate the efficacy of a probiotic, a mannan-oligosaccharide, an organic acid and their mixture on growth performance, intestinal microbiota composition, intestinal morphology and immune response. Pigs were randomly distributed into five treatments with four replicates of eight pigs per pen: control group was fed with a basal finishing diet, whereas the other groups received the same basal diet further supplemented either the probiotic at 35 mg/kg (2 × 1010 CFU/gr Enterococcus faecium), or the mannan-oligosaccharide at 1 g/kg, or the organic acid at 5 g/kg (containing 100% benzoic acid) or a mixture of the examined substances. At the end of the trial all pigs were weighed and slaughtered, and samples were taken for blood, histologic and microbiologic analyses. Total counts of aerobes and anaerobes, Lactobacilli, Bifidobacteria, Enterococci, Enterobacteriaceae and Coliforms, were enumerated by conventional microbiological techniques at both jejunum and cecum. Intestinal morphology was carried out in the jejunum, for villus height, crypt depth and goblet cells evaluation. Blood samples were evaluated by flow cytometry to assess the immune response of lymphocyte subpopulations.
The results showed that dietary inclusion of a mixture of probiotic, prebiotic and organic acid improved growth performance of fattening pigs while each additive alone did not have any significant effect. Jejunal villus height was also increased for the group that received the feed additive mixture compared to the mannan oligosaccharide group, although no differences were observed on goblet cell counts among the different groups. The inclusion of the E. faecium increased the enterococci counts in both group receiving the probiotic in digesta samples of both jejunum and cecum; however no differences were observed in the total B- and T-helper cytotoxic cell populations in the presence or absence of the nutritional factors studied, although their ratio (CD4/CD8) was decreased in the group that received the mixture of the feed additives.
In conclusion, dietary supplementation with a combination of probiotic, mannan-oligosaccharide and organic acid could promote growth in fattening pigs and improve their intestinal microbiota and functionality.
Giannenas, I., Doukas, D., Karamoutsios, A., Tzora, A., Bonos, E., Skoufos, I., Tsinas, A., Christaki, E., Tontis, D. and Florou-Paneri, P. (2016). Effects of Enterococcus faecium, mannan oligosaccharide, benzoic acid and their mixture on growth performance, intestinal microbiota, intestinal morphology and blood lymphocyte subpopulations of fattening pigs. Animal Feed Science and Technology, 220, 159-167. http://doi.org/10.1016/j.anifeedsci.2016.08.003