Currently, the search for alternative ways to replace synthetic feed additives with environmentally safe natural feed additives with specified nutrient compositions in animal husbandry is being intensively pursued all over the world, including Russia.
The article presents the results of the effect of using coniferous-energy feed additive in diets on the indices of nutrient digestibility, hematological, live weight dynamics, and average daily growth rate of calves. The experimental group was formed according to the principle of paired peers. Four groups of 5 animals in each were formed from the selected animals. The control group received the basic diet only, and the experimental group received basic diet plus a pine-energy daily feeding additive (experiments 1, 2, 3) with the dosages of 10, 15, and 20 at the beginning of the experiment and up to 56, 80, and 103 g per head per day at the end of the experiment, respectively. It was found that adding the coniferous-energy supplement from 15 to 80 g per calf per day from the 1st to the 6th month of age ensures the stable intensity of calf growth during the lactation period of breeding. It was concluded that feeding calves with the coniferous-energy feed additive improves metabolism and increases the growth energy and development of young cattle.