RESUMO
Dairy cows suffer insulin resistance following parturition and lactogenesis. Several researchers attempted to reduce insulin resistance via dietary and parenteral supplementations of different substances to promote metabolic performance of dairy cows. Due to mechanisms of actions of butaphosphan in combination with cyanocobalamin, we hypothesized that this compound may reduce insulin resistance of dairy cows following parturition; hence, the effects of the intravenous administration of butaphosphan and cyanocobalamin to prepartum dairy cows on their insulin resistance after calving were evaluated. Twenty-four multiparous Holstein dairy cows were enrolled 3 weeks prior to parturition and divided into four equal groups, including control (Ctrl) and butaphosphan and cyanocobalamin (B+C) 1, 2, and 3. Ctrl cows received 15 mL of 0.9% NaCl solution and B+C 1, 2, and 3 groups intravenously received 2, 4, and 6 mL/100 kg BW of 10% butaphosphan and 0.005% cyanocobalamin combination over three periods of 3 consecutive days, including 21-19, 12-10, and 3-1 days before calving, respectively. Intravenous glucose tolerance test was performed weekly 1, 2, and 3 weeks after parturition to evaluate the insulin resistance phenomenon. Circulating levels of glucose, insulin, non-esterified fatty acids (NEFA), and beta-hydroxybutyric acid (BHBA) were assessed 1, 2, and 3 weeks after calving. Ctrl cows were the most insulin-resistant group, and B+C1 group was the most insulin-sensitive, followed by B+C2 and B+C3 groups. The NEFA and BHBA levels in the B+C3 group were significantly lower than those in the other groups. In conclusion, intravenous administration of butaphosphan and cyanocobalamin to the late-pregnant dairy cows may reduce their insulin resistance after calving.
