日粮钙磷水平对笼养蛋鸡骨代谢及骨超微结构的影响

EFFECTS OF CALCIUM AND PHOSPHORUS LEVELS ON THE BONE MICRO-STRUCTURE AND METABOLISM OF LAYERS

选用56周龄新扬州鸡产蛋鸡600只,按2×2完全随机设计分为4组,分别饲喂不同钙磷水平(高钙低磷、高钙高磷、低钙低磷、低钙高磷)的玉米-豆粕型日粮,每组5个重复。用放免技术测定鸡蛋鸡内分泌变化,双能X射线测定鸡骨密度差别,并用扫描电镜观察鸡骨超微结构的区别,以对不同钙磷水平日粮下笼养蛋鸡骨代谢情况进行比较研究。结果显示,高钙高磷组产蛋率显著高于两低钙组(P<0.05);高钙高磷组雌二醇(E2)、胰岛素促生长因子-1(IGF-1)水平显著高于低钙低磷组(P<0.05);骨钙素(BGP)、甲状旁腺素(PTH)、降钙素(CT)各组间差异不显著;高钙高磷组胫骨指数极显著高于低钙低磷组(P<0.01);骨超微结构也明显优于低钙低磷组。研究表明,钙磷互作对笼养蛋鸡骨代谢有明显影响。日粮钙磷水平分别为3.5%和0.32%,两者比例约11∶1时,笼养蛋鸡生产性能、内分泌水平及骨密度最佳,骨超微结构最为理想。

New Yangzhou 56-week-old chickens of 600 were divided by 2 × 2 factor for the complete random into 4 groups with corn-soybean meal diet and different levels of calcium and phosphorus （high calcium and low phosphorus treatment, high calcium and high phosphorus treatment, low calcium and low phosphorus treatment, low calcium and high phosphorus treatment）, and each treatment had 5 repeats. The effects of calcium and phosphorus level on layers bone metabolism were studied by RIA, dual-energy X-ray and scanning electron microscopy. Results showed that the laying rate in high calcium and high phosphorus treatment was significantly higher than those with two low calcium treatment （ P 〈 0.05） ; estradid （E2）, insulin-like growth factor-1 （IGF- 1） level in high calcium and high phosphorus treatment was significantly higher than those with low calcium and low phosphorus treatment （ P 〈 0.05） ; The difference of bone gla protein （BGP）, Parathyroid hormone （PTH）, calcitonin （CT） among the treatments was not significant, the tibial index of high calcium and high phosphorus treatment was significantly higher than those of low calcium and low phosphorus treatment （ P 〈 0.01 ）, and the bone microstructure was also superior to low calcium and low phosphorus treatment. The studies also showed that the interaction of calcium and phosphorus significantly affected on bone metabolism of layers. When calcium and phosphorus level was 3.5 % and 0.32 % respectively, the production performance, endocrine, bone mineral density and bone microstructure of layers were desirable.