Effects of chestnut tannins supplementation of prepartum moderate yielding dairy cows on metabolic health, antioxidant and colostrum indices

This study investigated the effects of dietary supplementation with chestnut tannins (CNT) on metabolic and antioxidant status of prepartum cows along with their colostrum quality. Pregnant multiparous Holstein cows were paired according to parity and body condition score, and assigned either to a diet supplemented with 20 g/d of commercially available product containing chestnut tannins (CNT, n=20) or to an unsupplemented control diet (CON, n=20) for the last 25±2 d of pregnancy. Serum metabolite, insulin and antioxidant capacity indices were measured in blood samples taken at d 25 and d 5 before expected parturition. Chemical composition and IgG concentration were determined in colostrum samples collected from the first milking postpartum. The addition of CNT led to lower BUN (P=0.02) and consequently higher serum glucose (P=0.02) and insulin (P<0.01) concentrations which were associated with lower circulating NEFA (P<0.01) and BHBA (P<0.01) in CNT group than those of CON. The serum paraoxonase 1 (PON 1) activity and total antioxidant capacity (TAOC) were higher at -5 d in CNT than in CON (P<0.01, P=0.03; respectively). Close-up CNT improved lactose percentage and IgG concentration (P=0.03, P=0.04; respectively) and tended to improve percentage of protein and SNF (Solid Not Fat) in primary colostrum (P=0.06, respectively), without affecting colostrum fat and total solid (P=0.98, P=0.43; respectively). Supplementation of CNT in the diet during close-up period did not have adverse effects on metabolic profiles prepartum. Instead, this feeding regimen was more beneficial to antioxidant capacity and colostrum quality than feeding the control diet.