The influence of dcad value in feed ration on hypocalcaemia during transition period in cows – Review

Transition period (three weeks before calving and the first three weeks of lactation) is an intensive changes in the organism of cow which have to be accompanied by changes in feeding. One of the most important metabolic diseases of the periparturient and early lactation periods is hypocalcemia leading to postpartum paralysis. Among its many causes, there is high content of calcium in the feed ration during the dry period and the excess of cations, especially Na+ and K+ , in relation to anions (Cland S 2- ) in the feed. It results in too high blood pH, which impairs the activity of parathyroid hormone. Research results show that feeding negative cation-anion difference (DCAD – Dietary Cation-Anion Difference) ration reduces hypocalcaemia in cows in the postpartum period. In this review factors affecting DCAD values in the feed ration and possibilities of its optimization in the transition period has been discussed