Young calves in the first weeks of life (up to 5 weeks) should receive either whole milk or a milk-based milk replacer with flaxseed concentrate. If a farm can buy a high-quality milk replacer that includes milk protein and quality additives (and the price of the product is cheaper than whole milk), then it is better and more profitable to use milk replacer. In addition, whole milk has its drawbacks due to the insufficient amount of trace elements, especially iron. Milk replacer, in turn, is more balanced in nutrients and better adapted to the age of calves. To provide a calf with energy, it needs to be fed about 7 kg of whole milk or 1 kg of milk replacer per day. Therefore, the use of milk replacer not only solves the economic issue, but also improves the health of calves of different ages.