ABSTRACT 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.

中文翻译：

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日粮钙磷水平和添加25-羟基胆钙化醇对肉仔鸡开料性能和骨骼特性的影响

摘要 为了研究日粮钙 (Ca) 和磷 (P) 水平以及 25-羟基胆钙化醇 (25OHD3) 补充剂对肉鸡开食料性能和骨骼特性的影响，在 21 天的试验中使用了 224 只雄性 Arbor Acre 肉鸡。肉鸡被分配到 2 × 2 因子排列的四种处理中的一种，包括正常或低钙和磷的饮食，进一步补充或不补充 69 μg 25OHD3/kg 饲料。饲喂低钙和低磷日粮显着降低了锅炉的性能，并降低了胫骨和股骨的灰分、钙、磷和羟脯氨酸含量（p < 0.05）。在饲喂钙和磷缺乏的日粮的肉鸡中，极限负荷、弯矩、刚度和失效能量降低（p < 0.05）。添加 25OHD3 不影响生产性能，但显着增加了血清 25OHD3 水平。此外，添加 25OHD3 导致胫骨和股骨骨密度和股骨羟脯氨酸含量增加（p < 0.05），胫骨弯曲力矩增加（p < 0.05），股骨极限载荷和弯曲力矩增加（p < 0.05）。没有观察到骨骼特性的显着相互作用。总体而言，给肉鸡饲喂 69 μg/kg 饲料的 25OHD3 对肉鸡的生长性能没有影响，但部分改善了肉鸡发酵剂的骨骼生化和生物力学特性。