The study evaluated the effects of a Lactobacillus strains probiotic mix on performance, carcass traits, organs size, and intestinal microflora in broilers. A total of 200 one-day-old unsexed broilers were allotted into 2 groups with 5 replicates (20 broilers/replicate). During the feeding trial (35 d) the broilers were fed with a control (basal diet) or probiotic (basal diet plus 3% probiotic mix L. acidophilus and L. plantarum, 1:1 ratio). The probiotic supplementation did not significantly influence the performance, carcass traits and organs size of broilers at slaughter age. No effect of probiotic supplementation on visceral weight or length was observed, except a higher of jejunum (P=0.007) and ileum (P=0.013) weights, and a tendency to higher the caecum length (P=0.070). The probiotic mix had no significant effect on the intestinal pH, but it improved the microflora by decreasing the Enterobacteria and E. coli counts and increasing the Lactobacilli counts and Lactobacilli: E. coli ratio in the ileum and caecum (P<0.05). In conclusion, the probiotic mix (L. acidophilus and L. plantarum mix, 1:1 ratio) did not significantly affect the productive performance but had a positive effect on broilers’ gut microflora.
