EN
The sensitivity of a cow in the puerperal period to the occurrence of hypocalcaemia and paralyses is related to its breed and age. Positively correlated to the disease are DCAB balance, calcium and potassium contents; negatively correlated are fiber and sulfur contents. Because of the fact that the increased administration of anions decreases the absorption of Mg in cows during the puerperal period (which leads to decrease of Mg content in serum), the dose of calcium (1.0-1.2% Ca in dry matter) and magnesium (0.3-0.4% Mg in dry matter) should be increased during the application of anionic salts. However, high doses of calcium between 3-0 weeks before delivery can be used only when anionic salts are administered. Presently, high doses of D3 vitamin 5-7 days before delivery D3 are not used (capability toxic effect) and are limited by special regulations (UE and USA).