本文旨在评价使用CPM模型改善日粮能氮平衡和提高奶牛生产性能的效果。选择健康、胎次、体重和泌乳阶段相近的2组试验奶牛各28头，组日均产奶量分别为20和25 kg，按配对试验设计要求把试验奶牛分成对照组和试验组，对照组日粮为奶牛场当前的日粮，试验组日粮为应用CPM软件调整后的日粮。试验期为45 d。通过对比饲养试验检验CPM模型在日粮评价和预测奶牛生产性能方面的应用效果。试验结果表明，饲喂调整后日粮的奶牛产奶量、4%标准乳产量、乳尿素氮和血浆尿素氮含量均略高于对照组（P＞0.05），试验组Ⅰ的乳脂率略高于对照组Ⅰ（P＞0.05），二者乳蛋白率相似，试验组Ⅱ的乳脂率、乳蛋白率则略低于对照组Ⅱ（P＞0.05）；调整后2种日粮成本分别比调整前每天降低2.43元和2.12元。试验同样证明，利用CPM模型预测产奶量与实际产奶量的差距除了对照组Ⅰ之外，其他处理均在6%之内，预测DMI与实际DMI的差距在5%之内。由此可知，在我国规模化奶牛场应用CPM模型可以起到预测日粮的营养价值、改善日粮的能氮平衡、提高奶牛的生产性能和降低饲养成本的作用。因此，CPM模型在我国奶牛规模化饲养条件下应用是可行的。

The objective of this study was to evaluate CPM model in terms of improvement in performance of lactating cows by balancing dietary energy and protein. Fifty-six dairy cattle with similar lactation, age, body weight and health were selected, and average daily milk yield of half of cattle was about 20 kilograms, and that of another half was about 25 kilograms. According to matching experiment design, control diets were the diets of dairy farm, experiment diets were the diets adjusted by CPM model. The application effect of CPM model on evaluating diets and predicting the dairy cattle performance was examined by feeding trial. The trial lasted for 45 d. The results showed that, milk yield, 4% fat corrected milk yield, blood urea nitrogen （BUN） and milk urea nitrogen (MUN) contents in milk of the dairy cattle fed the adjusted diet were all slightly higher than those in control group (P>0.05). The milk fat rate in experimental group Ⅰ was slightly higher than that in control group Ⅰ (P>0.05), but both had similar milk protein rate. The milk fat rate and milk protein rate in experimental group Ⅱ were slightly lower than those in control group Ⅱ (P>0.05). Cost of the adjusted diets was decreased by ￥2.43/d and ￥2.12/d compared with original diets, respectively. The experimental results proved that error margin between milk yield predicted by CPM model and dairy cattle actual milk yield was in the range of 6 percentage except control group Ⅰ, and the error margin between DMI predicted by CPM model and actual DMI was in the range of 5 percentage. In conclusion, the CPM model could accurately predict diet nutritive value and improve diet energy nitrogen balance and increase diary cattle performance and decrease feeding cost. So it is feasible to apply CPM model in China large-scale dairy farms.［Chinese Journal of Animal Nutrition, 2010，22（2）:310-317］