EN
This study was conducted to evaluate the effectiveness of adding silicate mineral in feed on tibia bone characteristics and tibia, meat, as well as on faecal ash content in broilers. Four hundred and forty eight one-day-old broiler chicks were reared using a completely randomized design with seven treatments (diets containing 0, 1.5, or 3% of kaolin, bentonite, or zeolite) having four replicates of 16 birds each for 42 days. Body weight gain was significantly (P<0.05) increased in treatments with 3% kaolin and two levels of zeolite (1.5 and 3%) compared with 1.5% bentonite and control. Feed intake was significantly (P<0.05) higher in the treatment containing 3% bentonite compared with the treatments with 1.5% bentonite, 3% kaolin, and control. The feed conversion ratio was significantly better (P<0.05) in the treatment with 3% kaolin compared with 3% bentonite and control. Thickness of the wall in all treatments, except treatments with 1.5% kaolin and bentonite increased significantly when compared with the control (P<0.05). Treatments containing 3% bentonite or zeolite significantly improved the tibiotarsal wt/length index, robusticity index, and tibiotarsal index (P<0.05) when compared with the control. Tibia and meat ash as well as tibia and blood calcium contents increased significantly in treatments with 3% zeolite compared with the control (P<0.05). Also, the faecal ash content in the treatment with 3% zeolite decreased significantly compared with the control (P<0.05). Faecal dry mater in treatments with 1.5% kaolin, 3% bentonite or zeolite was significantly (P<0.05) higher than in the control. There were no significant (P>0.05) differences in tibia length, diaphysis diameter, medullary canal diameter, relative bone weight, tibia and meat dry mater, blood phosphorus, and tibia phosphorus among dietary treatments and control. In conclusion it seems that inclusion of a higher level (3%) of silicate mineral in diets is more effective than the lower level (1.5%) in improving tibia bone characteristics and ash in broiler chickens.