Evaluation of five models predicting feed intake by dairy cows fed total mixed rations

The five models predicted DMI in groups of dairy cows fed TMR with RMSPE ranging between 1.2 kg dry matter (DM) per day for the Gruber model to 3.2 kg DM per day for the Zom model. Evaluated across the experiment the ECT and the ER ranged between 0.3% and 65% and between 3% and 38% of MSPE, respectively. Error associated to ED ranged between 31% and 93% of MSPE. When all five models were evaluated for prediction of DMI both across and within experiments, results revealed that all five models predicted differences between diets within experiments better than differences across experiments. The Gruber model, which predicted DMI most accurately did so due to its negligible systematic error (ECT, ER) resulting in 93% of the error located in ED.