Effect of Anionic Salts in Prepartum Diets on the Ion Balance Statusand Lactating Performance of Dairy Cows

Twenty -eight Holstein breed cows were randomly assigned to anionic salt - or control prepartum diet to investigate the effect of anionic salt addition on the acid-base status, blood ion concentrations, retained placenta incidence, and lactating performance. The urinary pH value of the cows fed the anionic salt diet dropped quickly to 6 below after 5 days feeding, and was significantly lower than that of the cow fed the control diets (P0.01). Feeding anionic salt diets increased the concentration of Cl- in the plasma (p0.05) before parturition, and tended to increase the concentration of Ca2+. As anionic salt diets were fed, the retained placenta incidence decreased 31.2 percentage units (P=0.05) compared with the control diet. The animals fed the anionic salt diet had a bit higher fat-corrected milk yield during 1st, 2nd, 3rd and 4th milking months, also had a tendency of higher milk fat content, but had no significant influence on the content of milk protein, lactose and SNF (P0.2). The count of milk somatic cells was markedly decreased by feeding the diet with anionic salts (P=0.03(0.09) during the 2nd, 3rd and 4th milking months. It was concluded that the performance and health status of postpartum dairy cows can be improved when prepartum diets are supplemented with anionic salts.