This study details the relationship between maternal plasma oxidant-antioxidant enzymes with colostrum quality, serum gamma glutamyl transferase (GGT), immunoglobulin G (IgG) and IgM concentrations of calves in the different calving seasons. Holstein breed cows between two and eight lactations and their calves were enrolled in the study. Holstein cows calving in winter (n=45) and their calves (n=45) were assigned to the winter group, while cows calving in summer (n=45) and their calves (n=45) were assigned to the summer group. Samples for malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were collected on day -21±3 before expected calving and also on calving day (Day 0). IgG and the specific gravity of the colostrum were determined after calving. Serum GGT and IgG and IgM were measured before the feeding, with colostrum, of calves (0 hours) and also in the 24th hour following the feeding of colostrum. Plasma MDA levels at -21±3 and 0 days in the summer cows were determined to be higher. GSH-Px activity was higher in the winter cows. IgG levels and the specific gravity of the colos- trum were also higher in the winter cows. Calf IgG levels at the 24th hour of life were higher in the winter cows. In the winter group, IgM levels at 0 and 24 hours were also higher. While MDA was negatively correlated with IgG, IgM, GGT, IgG and the specific gravity of colostrum, GSH-Px activity had a positive correlation with IgG, IgM, GGT, IgG and the specific gravity of colostrum. The observed differences in plasma MDA, GSH-Px, calf serum IgG and IgM levels, and colostrum quality between both groups suggest a possible seasonal effect. The relationship between maternal oxidant-antioxidant enzymes, colostrum quality, and passive calf immunity revealed that these enzymes could be used as indicators in the evaluation of calf health and colos- trum quality.