Effects of vanadium supplementation on performance and metabolic parameters in periparturient dairy cows

Thirty-two multiparous Holstein cows were used from 4 week prior to calving through 4 week postpartum to investigate the effects of vanadium (V) supplementation on performance, production, and metabolic parameters. In a complete randomized block design set-up, after 1-week of an adaptation period, cows were assigned randomly to receive 1 of 4 V levels: 0, 0.04, 0.08, and 0.12 mg of V as vanadyl sulfate/kg of BW0.75. Performance parameters (BW, BCS, DMI, and energy balance) did not change by V supplementation. While there was no alterations in concentrations of milk component, milk yield increased quadraticaly as supplemental V level increased (P = 0.04). During neither the prepartum period nor the postpartum period, plasma insulin concentration was affected by the treatments. However, plasma glucose concentration increased and plasma NEFA concentration decreased in a quadratic fashion in response to increasing supplemental V level (P < 0.05). During early lactation, but not during late gestation, the insulin: glucose ratio decreased quadraticaly (P = 0.04). In conclusion, V may play a role in modulation of the action of insulin and metabolic biomarkers related to energy metabolism during the periparturient period.