A study was undertaken to evaluate the effect of prebiotic, probiotic and synbiotic
supplementation on intestinal microflora and histomorphology of broilers. One-day-old Avian
48 chicks (n=100) were randomly assigned to 4 treatments (25 birds/treatment) for 6 week
experiment. Each treatment consisted of 3 replicates (two replicate of 8 birds and one with 9
birds). Treatment groups were as follow: 1. Basal diet (control); 2. Basal diet plus Mannan-
Oligosaccharide (MOS) at levels of 2 g /kg of the starter diets and 0.5 g/kg of the grower
diets); 3. Basal diet plus probiotic (3 g/kg diet, Saccharomyces cerevisiae); and 4. Basal diet
plus the combination of pre and probiotics (synbiotic). On d 21 and 42, 3 birds per treatment
were sacrificed to evaluate gut morphology and microbiology. Duodenum, jejunum, ileum,
and cecum microflora composition and intestinal histomorphology were determined. The
final body weight (BW), weight gain, feed conversion efficiency were significantly (p<0.05)
higher in probiotic and synbiotic supplemented broilers compared with the control and
prebiotic groups. Concentrations of bacteria belonging to Lactobacillus spp. in the duodenum
and jejunum digesta at d 42 were significantly (P <0.05) higher in prebiotic supplemented
broilers compared with the control and synbiotic treatments. However, synbiotic
supplementation maintaining populations of unprofitable or potential pathogens (E. coli) at
relatively low levels (numerically) in the small intestinal and cecal digesta. In addition, the
total aerobes and coliform colony count were not significantly affected by any of the dietary
treatment. Morphology data for the small intestine showed that synbiotic supplemented broilers had significantly higher (p < 0.05) villus height in the duodenum, jejunum, ileum in comparison with the other treatments. The crypt depths were numerically (p > 0.05) decreased in duodenum and ileum in synbiotic supplemented broilers. In addition, the age had
significant effect on intestinal histomorphology. Moreover, the interaction between dietary
treatment and age did not affect (p > 0.05) any of the intestinal histomorphological parameters.