Ehsan Sheikhsamani - Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
Abolghasem Golian - Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
Saeed Zerehdaran - Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran

This study aimed to investigate the effects of nano-vitamin D۳ (NVD۳) and micro-vitamin D۳ (MVD۳) on performance and bone parameters in broiler chickens. A total of ۷۹۲ one-d-old Cobb ۵۰۰ male broiler chickens were randomly distributed in a completely randomized design according to a ۲×۶ factorial arrangement of ۱۲ dietary treatments with six replicates of ۱۱ chicks. The treatments were: basal diet (control); basal diet supplemented with ۱۰۰, ۲۰۰, ۴۰۰, ۸۰۰, and ۱۶۰۰ (IU/kg diet) commercial MVD۳; and a basal diet supplemented with the same levels of NVD۳. The basal diet consisted of ۰.۵% Ca and ۰.۲۵% non-phytate phosphorus and was free of vitamin D۳ supplement. There were significant differences (P < ۰.۰۱) in feed conversion ratio due to supplementation with NVD۳ from ۴ to ۱۰, ۱۱ to ۲۱, and ۴ to ۲۱ days of age compared to those receiving MVD۳. The chicks receiving NVD۳ had significantly (P < ۰.۰۱) higher live body weight (LBW) at ۲۱-d of age and daily weight gain from ۴ to ۲۱-d of age compared to MVD۳. The chicks receiving NVD۳ had a significantly (P < ۰.۰۱) higher concentration of ash and Ca content in the tibia. Bone stiffness and strength, tibia weight per length index, tibia weight, tibia diameter, organic matter (OM), OM/ash, and OM/length at ۲۱-d were significantly (P < ۰.۰۱) improved in birds fed diets supplemented with NVD۳. Relative bioavailability of the NVD۳ source to the MVD۳ was more efficient according to performance and bone mineralization measurements. There was better growth performance and bone parameters in the ۸۰۰ and ۱,۶۰۰ IU/kg levels of both kind than at the lowest level. Assessing the data of all experimental indexes showed that ۸۰۰ IU/kg exhibited significant linear effects, suggesting that it can be the ideal level of supplementation of NVD۳, and, on the other side, the rate of ۱۶۰۰ IU/kg could be the maximum supplementation of NVD۳ in broiler chickens.

Performance, Broiler chickens, Bone parameters, Nano-vitamin D۳, Micro-vitamin D۳