Effects of dietary calcium and phosphorus levels and supplementation of 25-hydroxycholecalciferol on performance and bone properties of broiler starters
2019
Zhang, Lianhua | He, Tengfei | Li, Miao | Hu, Jiangxu | Piao, Xiangshu
To investigate effects of dietary calcium (Ca) and phosphorus (P) levels and 25-hydroxycholecalciferol (25OHD₃) supplementation on performance and bone properties of broiler starters, 224 male Arbor Acre broilers were used in a 21-d trial. Broilers were allotted to one of four treatments in a 2 × 2 factorial arrangement including diets either normal or low in Ca and P, which were further supplemented or not with 69 μg 25OHD₃/kg feed. Feeding low Ca and P diets significantly reduced performance of boilers and decreased ash, Ca, P and hydroxyproline contents in tibias and femurs (p < 0.05). Ultimate load, bending moment, stiffness and energy to fail were decreased (p < 0.05) in broilers fed diets deficient in Ca and P. Addition of 25OHD₃ did not influence performance but significantly increased serum 25OHD₃ levels. Furthermore, the addition of 25OHD₃ caused an increased tibial and femoral bone density and femoral hydroxyproline content (p < 0.05), increased bending moment in tibias (p < 0.05), and enhanced ultimate load and bending moment in femurs (p < 0.05). No significant interactions were observed for bone properties. Overall, feeding 25OHD₃ at 69 μg/kg feed to broilers had no effect on growth performance but partly improved bone biochemical and biomechanical properties of broiler starters.
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