THE EFFECT OF MOLYBDENUM-INDUCED COPPER DEFICIENCY ON ACUTE-PHASE PROTEIN CONCENTRATIONS, SUPEROXIDE-DISMUTASE ACTIVITY, LEUKOCYTE NUMBERS,AND LYMPHOCYTE-PROLIFERATION IN BEEF HEIFERS INOCULATED WITH BOVINE HERPESVIRUS-1

This study was conducted to determine the effect of Cu deficiency on a cute-phase protein concentrations, superoxide dismutase activity, leuk ocyte numbers, and lymphocyte proliferation in heifers inoculated with live bovine herpesvirus-1 (BHV-1), Hereford x Angus heifers were allo tted by weight and initial liver Cu concentrations into molybdenum (Mo )-supplemented (n = 6) or control(n = 6) groups. Control heifers were fed a basal diet supplemented with Cu-sulfate to achieve a dietary con centration of 8 ppm of Cu. The Mo-supplemented heifers received the ba sal diet supplemented with Mo to achieve a dietary Mo:Cu ratio of 2.5: 1 and with sulfur at .3% of the diet. All treatments were delivered fo r 129 d, when heifers were inoculated intranasally with BHV-1. To ensu re adequate Cu stores before viral challenge, control heifers were giv en a cupric glycinate injection on d 100 of treatment. On d 129, Mo-su pplemented heifers were considered Cu-deficient (liver Cu = 23.2 and 9 0.1 ppm for Mo-supplemented and control, respectively). Neutrophils we re increased (P < .01) on d 129 in Mo-supplemented heifers. Ceruloplas min, a copper-dependent acute-phase protein, increased (P < .01) by 48 h after challenge in control but not in Mo-supplemented heifers. Fibr inogen, an acute-phase protein not containing copper, increased by 48 h after challenge in Mo-supplemented but not in control heifers. Eryth rocyte superoxide dismutase (SOD) activity was less (P < .05) in Mo-su pplemented heifers on d 129. Viral challenge had no effect on SOD acti vity. Lymphocyte proliferative response to phytohemagglutinin stimulat ion was greater (P < .01) for Mo-supplemented heifers following BHV-1 challenge. No differences were detected when lymphocytes were stimulat ed with concanavalin-A or pokeweed mitogens. These data indicate that Cu deficiency alters the acute-phase protein response to viral infecti on and may affect lymphocyte responsiveness to mitogen stimulation.