Evaluation of the dry matter intake predictions of the Cornell Net Carbohydrate and Protein System with Holstein and dual-purpose lactating cattle in the tropics

摘要: Abstract Data from three separate experiments were used to evaluate the dry matter intake (DMI) predictions of version 5.0 Cornell Net Carbohydrate and Protein System (CNCPS). Experiment 1 was conducted with 12 lactating Holstein cows confined in individual stalls, receiving known amounts supplements fresh, chopped Panicum maximum cv Tobiata grass. Experiments 2 3 13 crossbreed dual-purpose rotationally grazing Cynodon nlemfuensis Alicia P. grass, respectively, appropriate supplementation. Pasture estimated for an 8-day period using alkane technique. Model-predicted DMI based on measured feed analyses group animals very close observed values, a mean bias −0.19 kg DM per day, suggesting that adjustment by CNCPS model tropical conditions is accurate animals. The not as accurate. underpredicted 2, different degrees accuracy evident 3. For experiments, slope regression between predicted unity, but intercept significantly ( P