Redox balance in dairy cattle and their calves at birth and its relationship to colostral passive immunity

Newborn calves are exposed to oxidative stress (OS) just after birth, and yet the role of colostrum in OS is not well detailed. The redox indicators, total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI)] along with immunoglobulin-G (IgG) concentrations were assessed in 21 healthy Swiss Brown mother-calf pairs. Furthermore, alterations in theseparameters and IgG concentrations were analysed in an additional 23 healthy calves during the first 45 days of life (day 0 = at birth, 1, 3, 7, 14, 28 and 45). TAS and TOS concentrations were determined calorimetrically and IgG level by commercial ELISA kit. A negative correlation was determined between colostral IgG and serum maternal TOS (r:-0.49, P<0.05) and colostral TAS (r:-0.54, P <0.05). Calves exhibited elevated levels of TOS (8.29±0.30), TAS (0.71 ± 0.02) and OSi (1.20 ± 0.08) at birth. However these levels decreased after the 24th hour (6.72 ±0.2, 0.65 ±0.03, and 1.05 ±0.05, respectively) and remained stable throught the study. In conclusion, our results suggest that newborn calves experience OS after birth and colostral antioxidants may highlights its potential role in mitigating OS in these calves. The results may be of help in improving antioxidant capacity, either by treating dams during pregnancy or by treating colostrum with substances with antioxidant properties.