Effects of probiotic and phytogenic products on performance, gut morphology and cecal microflora of broiler chickens

Abstract. The trial involved 684 Cobb 500 broiler chicks in order to investigate the effects of probiotics and phytogenic additives on performance, gut morphology and cecal microbial concentrations. Birds were assigned to three treatments: control feed, treatment with addition of probiotics in feed and water and treatment with addition of phytogenic blend in feed. The results showed a significant improvement (P<0.01) in body weight gain and a numerical, but non significant (P>0.05) improvement in feed conversion ratio by adding both probiotics and phytogenics in feed. There were no statistically significant differences among treatments regarding total aerobes, anaerobes, lactic acid bacteria, bifidobacteria, enterococci, and Escherichia coli populations (P>0.05) in cecum of broilers. The gut morphology examination showed that probiotics had beneficial effect on jejunum morphology causing a significant (P<0.005) increase in villus height and villus surface area compared to other two groups. On the other hand, phytogenic additive had no effect (P>0.05) on villus height or villus surface area, but reduced the villus/crypt ratio (P<0.05), which may indicate that the improved production results in the group with added phytogenics are not directly connected with changes in gut integrity, but with other physiological mechanisms.