This study was conducted to assess the effects of systemic administration of bovine recombinant interleukin-8 (rIL-8) on whole body insulin resistance in Holstein bull calves. Additionally, blood metabolites and complete blood cells count were evaluated. Holstein bull calves (30 ± 6 d of life) were individually housed and randomly allocated into 1 of 2 treatment groups; rIL-8 (rIL-8, n = 10) and controls (CTR, n = 8). Calves assigned to the rIL-8 group received a total of 7 rIL-8 injections consecutively from d 1 to 4 (one s.c. injection followed by 6 i.v. injections at a dose of approximately 4 μg of rIL-8 per kg of body weight. Calves in the CTR group also received 7 injections but containing only sterile saline solution. To determine whether calves injected with rIL-8 were developing insulin resistance, 2 intravenous glucose tolerance tests (IVGTT) were conducted at 12 h, and 7 d after treatment cessation. Blood samples were collected at −30 (before injection, 0830 h), 30, 60, 120, 240 and 360 min after daily treatments during treatment days (d 1 to 4). Additionally, blood samples were collected daily (0830h) from d 5 to 10 (end of follow-up period). Serum was harvested and the following parameters were measured; β-hydroxybutyrate (BHB), nonesterified fatty acid, glucose, insulin, plasma urea nitrogen, haptoglobin, and complete blood cells count. Calves treated with rIL-8 had higher concentrations of insulin and higher positive area under the curve (AUC) in response to the glucose challenge when compared with controls. Moreover, BHB was significantly higher for rIL-8 calves than for CTR calves (rIL-8 = 3.54 ± 0.10 mg/dL; CTR = 2.99 ± 0.12 mg/dL). Treatment also affected the count of lymphocytes (rIL-8 = 4.52 ± 0.12; CTR = 3.84 ± 0.14 × 10³/μL), monocytes (rIL-8 = 0.87 ± 0.03; CTR = 0.67 ± 0.04 × 10³/μL), and granulocytes (rIL-8 = 3.54 ± 0.22; CTR = 2.66 ± 0.24 × 10³/μL). We conclude that systemic administration of rIL-8 induces strong and long lasting insulin resistance in milk fed Holstein bull calves. Moreover, we observed that systemic administration of rIL-8 alters blood metabolites and white blood cell population.