25-羟基胆钙化醇和耐热性植酸酶降低北京鸭日粮有效磷水平的研究

Effect of 25-hydroxycholecalciferol and phytase on phosphorus level of Beijing duck diet

为探讨25-羟胆钙化醇（25-OH-D3）和耐热性植酸酶联合使用降低北京鸭日粮有效磷水平的效果,选用10日龄雄性北京鸭480只,随机分为6个处理。试验前期（10～20 d）和后期（21～35 d）对照组日粮中有效磷质量分数分别为0.45%和0.38%（以下同）。负对照组1、负对照组2、试验组1、试验组2和试验组3有效磷水平在对照组日粮基础上分别减少0.05%、0.10%、0.10%、0.15%和0.20%。结果表明：1）试验前期日粮有效磷含量为、0.35%时,其20 d胫骨灰分率和胫骨强度都显著低于有效磷负对照组1（P〈0.05）,而有效磷水平为0.45%和0.40%之间对生产性能、骨骼发育指标等都没有显著差异。2）与0.40%的有效磷相比,随试验组日粮中有效磷水平的下降,试验前期粪磷（P）含量显著下降;同时当试验组日粮有效磷为0.25%时,导致试验前期日增重2、0 d胫骨灰分率及骨强度显著或极显著低于负对照组1。3）试验后期各处理组之间北京鸭生产性能和骨骼发育指标均没有显著差异。综合本试验结果得出：北京鸭日粮中同时添加70μg/kg 25-OH-D3与1 500 U/kg耐热性植酸酶可以替代有效磷0.10%～0.15%,节约日粮有效磷摄入量21.80%～38.23%,粪磷排放降低44.64%～50.00%。

This study involved six treatments,using diets supplemented with/without 70 μg/kg 25-hydroxy-cholecalciferol（25-OH-D3） and 1 500 U/g phytase.Each treatment was assigned to 8 pens of 10 d age male Beijing ducks.Growth performance,mineral contents of bone and serum,bone mineralization,bone breaking and litter P were determined at 21 and 35 d respectively.The results showed：1）There was no effect on performance and bone mineralization with decrease in concentrations of P（0.45%,0.4%）,while Beijing duck tibia ash and strength decreased significantly（P〈0.05） when fed with 0.35% P compared to diets with 0.4% P at 20 d.2）Compared to the group with 0.4% P in the diets,the concentration of fece P was decreased significantly during the period of 18 to 20 d with the decrease in concentrations of P（0.35%,0.3% and 0.25%） in diets supplemented with 25-OH-D3 and phytase,while weight gain（10 to 20 d）,tibia ash and strength decreased significantly（P〈0.01 or P〈0.05）.3）There was no effect on performance and bone mineralization between groups from 21 to 35 d of age.Based on above results,the optimum requirement of available P was 0.4% or 0.3% when diets supplementated with 70 ug/kg 25-hydroxycholecalciferol and 1 500 U/g phytase.