Holstein cows (n = 64) were used to evaluate effects of dietary SCFP (NutriTek, Diamond V, Cedar Rapids, IA) on oxidative status and immune response during the transition period. Control (CON; n = 30) or SCFP (n = 34) TMR were fed from −29 ± 5 to 42 d relative to calving (45% NDF, 14% starch prepartum; 32% NDF, 19% starch postpartum). Blood samples were collected during wk −4, −2, 1, 2, and 5 relative to calving. Oxidative status was evaluated in plasma by retinol and tocopherol concentrations, glutathione peroxidase activity (GPx), and Trolox equivalent antioxidant capacity (TEAC). Innate immune response was evaluated by PMA-stimulated oxidative burst capacity (OBC) and glycogen content of polymorphonuclear cells (neutrophils; PMN) isolated from blood. Ovalbumin was administered with adjuvant on d 7 and 21 postpartum, and adaptive immune response was evaluated by serum anti-ovalbumin IgG content on d 28 and 35. Mixed models were used to assess effects of treatment, time, parity, and all interactions. Treatment did not affect oxidative or immune parameters (all P > 0.05). There were no treatment × wk interactions except for plasma tocopherol concentration, which tended to be greater in SCFP cows during wk 2 (P = 0.06). There was a tendency for a treatment × parity interaction for anti-ovalbumin IgG concentrations, which tended to be greater in SCFP vs. CON primiparous cows (P = 0.08). Relationships among oxidative and immune measures were explored with regression techniques. In general, individual antioxidant measures weakly predicted TEAC (R² < 0.20), but GPx became a stronger predictor during wk 2 (R² = 0.31; P < 0.01). Blood glucose showed weak but positive associations with PMN glycogen content postpartum (R² = 0.14; P ≤ 0.001), but not prepartum (R² < 0.01). PMN glycogen did not predict OBC at any time point (R² < 0.05; P > 0.10). In this cohort of transition cows with low disease incidence, SCFP generally did not affect oxidative or immune parameters, antioxidant measures weakly predicted TEAC, and PMN function was not related to glycogen content.