应用CNCPS和NRC模型比较辽宁省不同奶牛场全株玉米青贮的营养价值

Comparison of nutrition values of whole-plant silage in different dairy farms in Liaoning using CNCPS and NRC models

试验采用常规化学分析方法、美国康奈尔大学净碳水化合物-净蛋白质体系(CNCPS)和NRC模型对辽宁省不同规模化奶牛场的全株青贮玉米营养价值进行评定。结果显示:辽宁省全株玉米青贮的常规营养成分干物质(DM)为31.12%、粗蛋白质(CP)为8.08%、粗脂肪(EE)为2.54%、粗灰分(Ash)为6.20%、粗纤维(CF)为31.53%、中性洗涤纤维(NDF)为47.08%、酸性洗涤纤维(ADF)为31.57%、非蛋白氮(NPN)为3.40%、中性洗涤不溶蛋白(NDICP)为1.72%、酸性洗涤不溶蛋白(ADICP)为0.86%、酸性洗涤木质素(ADL)为3.32%、淀粉(Strach)为26.07%;不同奶牛场制作的全株玉米青贮EE差异显著(P<0.05),其余各指标差异极显著(P<0.01)。CNCPS各组分中,碳水化合物(CHO)、快速降解碳水化合物(CA)、中速降解碳水化合物(CB1)、慢速降解碳水化合物(CB2)、非蛋白氮(PA)、快速降解真蛋白(PB1)、中速降解真蛋白(PB2)、慢速降解真蛋白(PB3)、不可被降解蛋(PC)在不同奶牛场间有极显著差异(P<0.01)。通过NRC模型对其进行蛋白和能值预测,发现辽宁省不同规模化奶牛场制作的全株玉米青贮均为瘤胃能氮平衡(RENB)正平衡日粮,且各场间RENB值差异极显著(P<0.01)。研究表明,辽宁省不同奶牛场制作的全株玉米青贮营养成分均有显著差异,配制饲料前应对其进行化验分析,使青贮玉米得到更有效的利用;辽宁省不同奶牛场制作的全株青贮玉米均为RENB正平衡日粮,在使用时需要注意配合适量的蛋白质饲料。

The experiment used conventional chemical analysis methods, Cornell University Net Carbohydrate-Net Protein System(CNCPS) and NRC model to evaluate the nutritional value of whole-plant silage corn on different scale dairy farms in Liaoning Province. The results showed that the conventional nutrient components of whole plant silage corn in Liaoning Province were dry matter(DM) 31.12%, crude protein(CP) 8.08%, ether extract(EE) 2.54%, crude Ash6.20%, crude fiber(CF) 31.53%, neutral detergent fiber(NDF) 47.08%, and acid detergent fiber(ADF) 31.57%,non-protein nitrogen(NPN) 3.40%, neutral detergent insoluble protein(NDICP) 1.72%, acid detergent insoluble protein(ADICP) 0.86%, acid detergent lignin(ADL) 3.32%, and Strach 26.07%. The EE of whole plant silage corn produced by different dairy farms was significantly different(P<0.05), and the other indicators were extremely different(P<0.01).Among the various components of CNCPS, total carbohydrate(CHO), rapidly degraded carbohydrate(CA), intermediately degraded carbohydrate(CB1),slowly degraded carbohydrate(CB2), non-protein nitrogen(PA), rapidly degraded true protein(PB1),intermediately degraded true protein(PB2), slow degraded protein(PB3) and conjugated protein(PC)have extremely differences among different dairy farms(P<0.01). The protein and energy values were predicted by NRC model, and it was found that the whole corn silage produced by different large-scale dairy farms in Liaoning Province was the rumen energy and nitrogen balance(RENB) positive balance diet, and the RENB values were extremely different among different farms(P<0.01). The experiment indicates that there are significant differences in the nutritional components of whole-plant silage corn produced by different dairy farms in Liaoning Province. Laboratory analysis before compound feed can make it more effective. The whole plant silage corn produced by different dairy farms in Liaoning Province is a energy nitrogen balance value(RENB) positive balance diet, which is necessary to pay attention to the appropriate amount of protein feed when using it.