Performance, nutrient digestibilities, and metabolic profiles of Holstein calves fed whole milk or milk replacer at two feeding levels.

The macronutrient composition of common milk replacers (MR) largely differs from bovine whole milk (WM). These differences are more nutritionally relevant when calves receive higher milk allowances. Therefore, the present study compared fresh WM with a conventional MR fed at 2 level of feeding allowances evaluating growth performance, apparent total-tract nutrient digestibilities, nitrogen (N) balance, and serum metabolite profiles in calves.