Under conventional milk feeding systems, calves are provided restricted amounts of milk or milk replacer and weaned after a few weeks of age. With increasing awareness that early nutrient intake may increase milk yield in first lactation, high milk replacer schemes in early life are currently intensively researched. In the veal industry, high milk replacer schemes for calves are common practice, but in Europe, the intake of concentrates in this sector is strongly increasing, at the expense of milk replacer. Combining knowledge on nutrient metabolism of these areas provides valuable insights for future development of targeted feeding schemes for young calves. Protein efficiency in calves drops dramatically in early life, particularly related to metabolic inefficiencies. Typically for calves and unlike in monogastric species, protein and energy simultaneously limit protein retention. With the possible exception of the first weeks of life, amino acid imbalance is rarely a cause of protein inefficiency. Fats and lactose are well digested, but digestion of starch appears limited. After absorption, fats are oxidized or stored as body fat, but lactose is predominantly oxidized. Recently, it was revealed that calves do possess the enzyme systems for de novo lipogenesis from glucose, but use it only at very high lactose intakes. Consequently, the increase in fat deposition following an increase in feed intake is almost exclusively from dietary fat. Insulin sensitivity rapidly drops in the first 6 weeks of life to levels that are invariably low. This decrease seems independent of diet, as it occurs in milk fed as well as in weaned calves. Meal responses of glucose and insulin largely reflect portal glucose appearance rather than insulin sensitivity. Nonetheless, available glucose is virtually completely oxidized. Apparently, despite the low insulin sensitivity, glucose transport into cells is almost complete. In veal calves of 4-6 months of age, the efficiency of utilization of lactose, fat and protein for growth was found to be independent of the level of intake of solid feeds, suggesting that feeding scheme’s for milk (replacers) and solid feeds for calves may be developed independently.