Effect of phytase producing Bacillus subtilis SH17-3, phytase enzyme and a commercial probiotic on the performance of broiler chickens fed low phosphorus diets

The aim of this study was to evaluate the efficacy of Bacillus subtilis bacteria capable to produce phytase enzyme on improving broiler chickenperformance and to evaluate its effect on gastrointestinal organs, and tibia strength in broiler chickens. This experiment was done using 200 one-dayold broiler chicks (Ross 308), in a completely randomized design with 5 treatments, 4 replicates and 10 chicks per replicate for 42 days. Thetreatments include: 1) positive control diet containing sufficient phosphorus level; 2) negative control diet with 30% less phosphorus; 3) negativecontrol diet supplemented with phytase enzyme; 4) negative control diet supplemented with a commercial probiotic; 5) negative control dietsupplemented with Bacillus subtilis SH17-3. Feeding broiler chickens with a diet containing Bacillus subtilis bacteria SH17-3 significantly reducedfeed intake and mean body weight gain (BWG) in the total rearing period (P<0.05). Feeding broiler chickens with a diet containing phytase enzymesignificantly increased feed intake and BWG (P<0.05). The strength of tibia was significantly increased in birds received phytase enzyme, comparedto other groups (P<0.05). Based on the results the use of phytase enzyme in diets with phosphorus deficiency, improves performance in broilers; butBacillus subtilis bacteria SH 17-3 could not be a good alternative for probiotic and also phytase enzyme.