Colostrum from primiparous Holstein cows shows higher antioxidant activity than colostrum of multiparous ones

摘要

Antioxidant components of colostrum prevent oxidative cell damage caused by free radicals that could harm the calf s development. The relationship of antioxidant potential of colostrum with parity is not well defined and could enlighten the importance of these components for the neonate and for the protection of the intestinal epithelium. The purpose of this work was to determine the antioxidant potential of colostrum from primiparous and multiparous Holstein cows in a commercial dairy farm. Samples from the first milk secretion from primiparous (first lactation, n = 8) and multiparous (second and third lactations, n = 8) Holstein cows were collected after birth of calves for determination of immune and antioxidant factors. The cows sampled in this study were vaccinated during pregnancy in order to improve colostrum quality. Colostrum from primiparous cows showed higher values of ceruloplasmin activity, oxygen radical absorbance capacity (ORAC) and transferrin saturation index (TSI) than colostrum from multiparous cows (P＜0.05). The total iron binding capacity (TIBC) and transferrin concentration in the colostrum of primiparous cows showed a non-significant numerical decrease (P = 0.06) in relation to the value in the colostrum of multiparous cows. Concentration of proteins, immunoglobulin G, and activity of lactoperoxidase, lyso-zyme, glutathione peroxidase and catalase, in turn, did not differ (P ＞ 0.05). Metabolic differences between primiparous and multiparous cows may have affected the antioxidative status of colostrum, since ORAC values were twice higher in first lactation cows. Lower values of transferrin and TIBC and higher TSI in colostrum from primiparous cows suggests a relationship between lower iron stock and higher antioxidant activity. Thus, this work indicates an important role of the antioxidant potential of colostrum for neonates from first-lactation cows. Additionally, the iron stock may be directly related to the higher antioxidant potential of the colostrum from primiparous cows, and further investigations are required.