The objective of this study was to determine the impact of antibiotics and selected probiotics on the morphological properties of the small intestinal mucosa in growing-finishing pigs. Two production experiments were conducted on 32 hybrid fatteners (16 pigs per experiment, of 8 gilts and young hogs each, at a 1:1 ratio) fed complete diets in a 2-phase system. The animals were clinically healthy and had been treated for parasites prior to fattening. In the first experiment, diets were supplemented with the antibiotic flavomycin (group C1) and the probiotic ToyoCerin (Bacillus toyoi strain) (group E1) at the amount of 0.1%, and in the second experiment with flavomycin (C2) and Bactocell (Pedicoccus acidilactici, MA18/5M strain) (E2) at the amount of 0.01%. A histological analysis of small intestinal epithelial sections was performed using bax, bcl-x, bcl-2 polyclonal antibodies and Ki-67 and PCNA monoclonal antibodies. Sections of the duodenum, jejunum and ileum were prepared post mortem. Haematoxylin and eosin H-E, histochemical (PAS-Alcian Blue) and immunohistochemical staining procedures were applied. The results of histological, histochemical and immunohistochemical examinations of the small intestinal mucosa indicated that feed additives and probiotics had a varied effect on the morphological characteristics and the proliferation capacity of crypt epithelium. Enterocyte proliferation in crypt epithelium decreased after the administration of probiotics. The absence of significant differences between groups (C1-E1; C2-E2) may suggest that probiotics have no adverse effect on mucosal epithelial cells. Nevertheless, given the importance of this topic and the development of the use of feed additives, follow up research in this area is needed.
Feed additives, fatteners, small intestine, goblet cells, bax, bcl-x, bcl-2, PCNA, Ki-67Nutritional factors and bacterial populations colonizing the gastrointestinal tract modify the intestinal microstructure (Vitini et al. 2000) and induce functional changes in the intestinal mucosa (Babinska et al. 2005). Researchers vary in their opinions on the probiotic effect of bacteria on the intestinal epithelium. Baum et al. (2002) and Budiño et al. (2005) demonstrated that Saccharomyces boulardii and Bacillus cereus var. Toyoi strains had a beneficial influence on the epithelial structure, crypt morphology, number of Ki-67 positive cells and total mucosal cell counts, including cells secreting acidic and neutral mucopolysaccharides. Reiter (2006) did not observe any changes in the small and large intestine as a result of the supplementation of diets fed to sows and piglets with Enterococcus faecium strains. Lodemann et al. (2006) found that probiotics had a positive effect on animals. The findings of Pérez-Conesa et al. (2007) who studied rats administered probiotics, prebiotics and synbiotics indicate that feed additives significantly modify the depth of crypts in the proximal and distal colonic segments, and improve calcium, magnesium and phosphorus absorption. Rekiel et...