Aim: The aim of the study was to determine the efficacy of phytase and vitamin D supplementation in low phosphorous diet on performance and bone mineralization in broiler.

Materials and Methods: A total of 240 one-day-old broiler chicks were divided into 8 groups (A, B, C, D, E, F, G and H) with 3 subgroups in each, comprising 10 birds in each subgroup. Group A was fed normal basal diet having normal phosphorous ratio (Control) and group B was fed diet without inorganic phosphorous and phytase supplementation (Negative control). Group C, D E were offered diet containing only three levels of phytase (250, 500, 750 phytase unit (FTU)/kg feed) and group F, G and H were offered diets having three levels of phytase (250, 500, 750 FTU/kg feed) in combination of vitamin D3 (4000, 5000, 6000 IU/kg feed) respectively.

Results: The phytase and vitamin D3 supplemented groups (particularly, supplementation of 500 FTU/kg plus 5000 IU/kg) showed increased (P<0.05) live weight gain, dressing percentage, keel and shank length, toe and tibia ash percentage, calcium and phosphorous level in blood plasma; improved (P<0.05) feed conversion ratio as compared to the group A and B. Moreover, supplementation of phytase and vitamin D3 at 500 FTU/kg plus 5000 IU/kg was most economical as cost/kg live weight than 250 and 750 FTU/kg diet supplementation.

Conclusion: It may be concluded that 500 FTU/kg phytase + 5000 IU/kg vitamin D3 supplementation to low-P diet improved growth performance, carcass weight and bone mineralization in broilers.