IMPACT OF PROBIOTIC SACCHAROMYCES CEREVISIAE VAR. BOULARDII RC009 ALONE AND IN COMBINATION WITH A PHYTASE IN BROILER CHICKENS FED WITH ANTIBIOTIC-FREE DIETS.

The aim of the study was to assess the impact of the Saccharomyces boulardii RC009 alone and in combination with a phytase on productive performance, biochemistry, apparent ileal phosphorus digestibility, genotoxicity and histomorphometric parameters in replacement of growth-promoting antibiotics. Two hundred and four 1-day-old male broiler chickens were weighed and redistributed in 3 replicates per treatment with 17 broilers chickens each. Throughout the 49-day experimental period, the broiler chickens were provided with both starter and finisher diets corresponding to each treatment. Treatments (T) were T1: basal diet (BD - control with AGP); T2: BD (without AGP) + S. boulardii RC009 (200g/T, 1 x 1012 CFU/T feed); T3: BD (without AGP) + S. boulardii RC009) + phytase (1000 FTU/T); T4: BD (without AGP) + phytase. The results showed that all treatments were able to improve the productive parameters studied such as DWG and DFI (P=0.05) when compared to the control. The T3 had the highest value followed by T4 and T2. The best value of CI was obtained for T2 followed by T3 and T4. There is no effect of the probiotic or the enzyme alone or in combination on the biochemical parameters evaluated. The treatment T3 improved the weight of leg-thigh and poultry breast (P=0.05). The digestibility of phosphorus showed significant differences between treatments (P=0.05). The histomorphometric parameters were significantly influenced, impacting both the radio and absorptive surface areas, T3 had the best absorptive surface area. The frequency of micronucleus in bone marrow cells of broiler chickens was not affected by any of the studied treatments. The utilization of S. boulardii RC009 alone or combined with phytase notably enhanced productivity parameters, economically significant carcass weight, and histomorphometric characteristics in the small intestine. Moreover, they did not exert toxicity. These results suggest their promising potential for use either independently or in combination as substitutes for antibiotic growth promoters. [ABSTRACT FROM AUTHOR]