2003. Total antioxidant capacity: A tool for evaluating the nutritional status of dairy heifers and cows. Can. J. Anim. Sci. 83: 605-608. The nutritional status of dairy heifers and cows in Nova Scotia and Ontario was evaluated by measuring the total antioxidant capacity (TAC) of plasma antioxidants. Lactating cows had higher TAC levels compared to dry cows (P < 0.005). The TAC levels in cows were higher in Ontario compared to Nova Scotia (P < 0.001), and varied with changes in seasons, being highest in winter and summer in Nova Scotia and highest in the fall and spring in Ontario (P < 0.001).