Blood plasma mineral profile and health status in postpartum cows fed an anionic diet before parturition

The effects of an anionic versus cationic (control) diet on plasma mineral levels and health status were investigated in 24 dry pregnant Holstein-Friesian cows during the last 3 weeks of pregnancy. The cows were in their third or fourth parity, had a moderate level of milk production in their previous lactation, and did not have a history of milk fever. The anionic diet significantly improved plasma calcium status, as compared to the control (2.18 vs. 1.99 mmol L-1) and nonsignificantly reduced the incidence of subclinical hypocalcemia (1/12 vs. 5/12) without affecting other periparturient diseases. Other plasma mineral levels were unaffected, except chloride, which was higher in the anionic group. The results show that an anionic diet could improve calcium status around the time of parturition and reduce the incidence of subclinical hypocalcemia when fed to moderate producing dairy cows not predisposed to milk fever.