EFFECT OF CALF HOUSING ON PLASMA ASCORBATE AND ENDOCRINE AND IMMUNE FUNCTION

The effect of housing calves in indoor metal pens (1.2 m x 1.2 m) or commercial calf hutches was determined on plasma concentration of cortisol, antibodies, and ascorbate. Six calves per treatment were deprived of colostrum, assigned randomly to treatment, and fed a commercial milk replacer until 56 d of age. Calves housed in hutches had higher plasma IgG concentrations than calves in pens at 42 and 56 d of age. Housing had no effect on plasma IgM concentration. Antibody titers to keyhole limpet hemocyanin injected at 14 and 28 d of age were higher in hutch-housed calves from 21 to 56 d of age. Calves housed in hutches also had lower plasma cortisol concentrations, although cortisol decreased with age in both treatment groups. Plasma ascorbate and ascorbate plus dehydroascorbate were higher in hutch-housed calves. Regression analysis indicated a positive relationship between plasma ascorbate and IgG in metal pen-housed calves and a negative relationship in hutch-housed calves. Housing in 1.2 m x 1.2 m metal pens decreases cortisol, plasma ascorbate, IgG, and specific antibody titers in dairy calves relative to calves housed in hutches.