An Arg × infection interaction was observed for the levels of ALB, TC (both P < 0.001) and MDA (P = 0.003) in the blood of turkeys: C. perfringens infection increased the levels of ALB, TC and MDA at the medium and highest Arg content (Arg100 and Arg110, respectively), but not at the lowest Arg content (Arg90). The gene discussed is ALB; the disease is infection.