In birds during the reproductive period, calcium metabolism occurs about 20 times faster than in mammals, and calcium is extracted from the blood almost 5 times faster. During the first 3-4 weeks, the formation of a vertebrate animal in the fertilized egg occurs without any nutrients from the mother's body. Extrauterine embryonic development of the bird is possible only due to the high balance in the egg of nutrients, including minerals. Sources of mineral elements for the embryo are all components of the egg - yolk, protein and shell. Over 80% of the calcium in the embryo comes from the shell. This indicates the need for strict control over the mineral usefulness of the breeding egg used for incubation. In the postembryonic period in young animals, the percentage of most mineral elements in the body increases; the consumption of macro- and micronutrients per unit of weight increases while reducing their deposition in the body; indicators of the mineral composition of the blood are stabilized. The bird is characterized by a higher level of absorption of most macronutrients than in mammals. The apparent absorption of calcium in chickens reaches more than 60%, while the absorption of manganese is 2-5%. In this regard, due to abnormal mineral nutrition in a productive bird, mineral metabolism is quickly disrupted, egg laying is reduced and other symptoms of mineral deficiency are manifested. Of mature males, the intensity of mineral metabolism and the degree of assimilation of mineral elements by the body are low. The skeleton of a bird not only performs the function of homeostasis inherent in all vertebrates, but also directly participates in the formation of the egg. This function of the skeleton is sometimes so intense that it is carried out to the detriment of its strength. The system of endocrine regulation of mineral metabolism in birds is extremely specific and consistent. We are talking about the hormones of the pituitary gland, thyroid gland, parathyroid glands, bronchial bodies, sex and adrenal glands. The corresponding endocrine glands interact with each other and with other factors (in particular, vitamin D), regulating the metabolism of mineral elements at all levels: in the digestive canal, in extracellular fluids, in tissues, in excretory organs.