河南省小麦肉鸡代谢能预测方程的建立

Prediction Equations of Metabolizable Energy of Wheat in Henan Province for Broilers

本试验采用化学分析和肉鸡代谢试验建立了河南省小麦养分含量与代谢能的回归方程。试验1:选取河南省11种不同的成熟小麦,测定概略养分含量和容重,分析养分含量变化范围。试验2:用小麦、次粉、麸皮、面粉按照总戊聚糖含量梯度配制人工小麦,再添加一定量的维生素和矿物质,配制成人工小麦代谢饲粮。选取常规饲养的商品代罗斯308雄性白羽肉鸡进行代谢试验,分别在11~13日龄和25~27日龄,用全收粪法测定人工小麦代谢饲粮的表观代谢能(AME)、真代谢能(TME)、氮校正表观代谢能(AMEn)和氮校正真代谢能(TMEn),并采用逐步回归法建立AME、TME、AMEn和TMEn的回归方程。结果表明:1)河南省小麦粗脂肪(EE)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)及总磷(TP)含量的变异系数相对较大,分别为16.67%、15.84%、14.96%、19.32%。2)肉鸡对人工小麦代谢饲粮的养分表观代谢率在11~13日龄和25~27日龄存在差异,25~27日龄肉鸡对人工小麦代谢饲粮ADF、粗纤维(CF)的表观代谢率高于11~13日龄,AME、TME、AMEn和TMEn也高于11~13日龄。3)采用逐步回归法建立河南省小麦肉鸡代谢能的预测方程为:11~13日龄,AME=14.628-0.184NDF(R2=0.842,P<0.01),TME=15.49-0.197NDF(R2=0.854,P<0.01),AMEn=14.571-0.184NDF(R2=0.847,P<0.01),TMEn=15.49-0.197NDF(R2=0.854,P<0.01);25~27日龄,AME=15.462-0.217NDF(R2=0.797,P<0.01),TME=16.124-0.214NDF(R2=0.809,P<0.01),AMEn=15.179-0.208NDF(R2=0.801,P<0.01),TMEn=16.123-0.214NDF(R2=0.809,P<0.01)。4)通过预测方程计算所得人工小麦代谢饲粮AME、TME、AMEn和TMEn的预测值与实测值很接近,计算所得的河南省小麦AME、TME、AMEn和TMEn符合预期值。由此得出,不同品种河南省小麦之间EE、NDF、ADF及TP的含量差异相对较大;不同日龄阶段的肉鸡对小麦代谢能存在差异,设计肉鸡饲粮配方时,不同阶段饲粮代谢能应采用对应的代谢能值;低于14日龄的肉鸡,预测方程为AME=14.628-0.184NDF,TME=15.49-0.197NDF,AMEn=14.571-0.184NDF,TMEn=15.49-0.197NDF;14日龄以上的肉鸡,预测方程为AME=15.462-0.217NDF,TME=16.124-0.214NDF,AMEn=15.179-0.208NDF,TMEn=16.123-0.214NDF。

This study aimed to establish the regression equations for metabolizable energy of wheat in Henan province for broilers based on nutrient contents by the methods of chemical analysis and metabolic test for broilers.In trial 1,eleven kinds of mature wheat in Henan province were used to measure the nutrient contents and volume-weigh,and to analyze the variation ranges of nutrient contents.In trial 2,artificial wheat metabolizable diets were formulated by artificial wheat and a certain amounts of vitamins and minerals,and the artificial wheat were formulated by wheat,wheat middling,flour and wheat bran based on the graded level of total pentosan.Rose 308 broilers raised as normal production were used to complete metabolism test at 11 to 13 days of age and 25 to 27 days of age by the total collection method.The apparent metabolizable energy (AME),true metabolizable energy (TME),nitrogen corrected apparent metabolizable energy (AMEn) and nitrogen corrected true metabolizable energy (TMEn) of artificial wheat metabolizable diets for broilers were measured,and the stepwise regression method was used to establish regression equations for AME,TME,AMEn and TMEn. The results showed as follows: 1) the variance coefficients for the contents of ether extract (EE),neutral detergent fiber (NDF),acid detergent fiber (ADF) and total phosphorus (TP) of wheat in Henan province were relatively larger,and they were 16.67%,15.84%,14.96% and 19.32%,respectively.2) There were differences in the nutrient apparent digestibility of artificial wheat metabolizable diets for broilers between 11 to 13 days of age and 25 to 27 days of age.Among them,broilers fed artificial wheat metabolizable diets at 25 to 27 days of age had greater ADF and crude fiber (CF) apparent digestibility than those at 11 to 13 days of age,and the AME,TME,AMEn and TMEn at 25 to 27 days of age were higher than those at 11 to 13 days of age.3) The prediction equations for metabolizable energy of wheat in Henan province for broilers using stepwise regression method showed as follows: AME=14.628-0.184NDF ( R 2=0.842, P <0.01),TME=15.49-0.197 NDF ( R 2=0.854, P <0.01),AMEn=14.571-0.184NDF ( R 2=0.847, P <0.01) and TMEn=15.49-0.197NDF ( R 2=0.854, P <0.01) for 11 to 13 days of age;AME=15.462-0.217NDF ( R 2=0.797, P <0.01 ),TME=16.124-0.214NDF ( R 2=0.809, P <0.01),AMEn=15.179-0.208NDF ( R 2=0.801, P <0.01 ) and TMEn=16.123-0.214NDF ( R 2=0.809, P <0.01) for 25 to 27 days of age.4) The calculated values of AME,TME,AMEn,and TMEn for artificial wheat metabolizable diets using prediction equations were close to the measure values,and the calculated values of AME,TME,AMEn and TMEn for wheat in Henan province met the excepted values.In conclusion,the difference of contents of EE,NDF,ADF and TP of wheat in Henan province are relatively larger among different varieties.The metabolizable energy of wheat in different ages of broilers is different,when designing broiler diet formula,the metabolizable energy of diet should be correspondingly used in different stages.The prediction equations for AME,TME,AMEn and TMEn of wheat in Henan province are AME=14.628-0.184NDF,TME=15.49-0.197NDF,AMEn=14.571- 0.184NDF and TMEn=15.49-0.197NDF for broilers less than 14 days of age,and AME=15.462-0.217NDF ,TME=16.124-0.214NDF,AMEn=15.179-0.208NDF and TMEn=16.123-0.214NDF for broilers more than 14 days of age.