M Ebrahimi - Department ofAnimal Sciences, Faculty of Agriculture Science and Engineering, University ofTehran, Karaj, Iran.
A Towhidi - Department ofAnimal Sciences, Faculty of Agriculture Science and Engineering, University ofTehran, Karaj, Iran.
M Ganjkhanlou - Department ofAnimal Sciences, Faculty of Agriculture Science and Engineering, University ofTehran, Karaj, Iran.
M Amini - Department ofAnimal Sciences, Faculty of Agriculture Science and Engineering, University ofTehran, Karaj, Iran.

The objective of this study was to determine the effects of supplemented selenium (Se) on plasma cortisol, red blood cell glutathione peroxidase activity (RBC GSH-PX-1), concentration of immunoglobulinG (IgG) and body weight in pneumonic suckling calves.Ten Holstein suckling male calves were randomly allocated to two groups and fed either unsupplemented milk (control) or with milk supplemented with 0.3 mg/kg DM Se (Sel-Plex) for two months. Sel-Plex had no significant effect on cortisol plasma concentration.Asignificant increase in red blood cell GSHPX- 1, body weight and serum concentration of IgG was observed in the treated group, along with a non-significant increase in body weight. The results indicate that Sel-Plex supplementation of suckling calves with a marginal selenium status increases GSH-PX-1, serum concentration of IgG and body weight of calves

Calf; glutathione peroxidase activity; IgG;selenium;weight gain