Journal: Journal of Animal Science: 1989 67: 557-564.
Abstract: The present study was conducted to determine whether a marginal Se deficiency affects health, blood characteristics and theimmune response of calves subjected to stresses associated withweaning, shipping (332 km) and Pasteurella hemolyticainoculation. Treatments were 1) –Se, 2) –Se/P. hemolytica, 3) +Se (.1 mg Se/kg feed) and 4) +Se/P. hemolytica. Previous Se intake was controlled; dams of –Se calves were fed diets marginally deficient in Se (.03 to .05 mg/kg), whereas dams of +Se calves received a s.c. injection of 30 mg Se (as sodium selenite) every 60 d. Calves were inoculated with P. hemolytica intratracheally on d 3 following weaning and transport. Inoculation with P. hemolytica increased (P< .05) body temperatures, platelet counts, serum IgM concentrations and serum antibody titers and decreased serum albumin concentrations at 4 to 7 d postinoculation. Weight gains for the 21-d study were not affected by Se status, although whole blood and plasma glutathione peroxidase (GSH-Px) were higher (P < .05) for +Se calves. Plasma GSH-Px increased (P < .01) in calves showing signs of morbidity. Increases in plasma GSH-Px were correlated positively with body temperature. Serum IgM concentrations were higher (P < .05) in +Se calves on d 17, but Se-supplemented calves had lower (P < .05) anti-P. hemolytica titers on d 17 than –Se calves. Selenium status did not affect body temperatures, plasma creatine phosphokinase or serum IgG and albumin concentrations. These results indicate that Se status can affect IgM concentrations following stress.