at birth and greater fecal scores for wk 2 and 3 than did male calves. Gender did not affect serum protein, IgM, or IgG; however, female calves had higher percentages of monocytes and lower percentages of T cells than did male calves. At 6 wk, female calves also had higher percentages of B cells than did male calves. These data indicate that ratios of vitamins A and E should be considered in dietary formulations for calves. Also, additional vitamin A provided by some scour treatments could be detrimental to calves that are already receive vitamin A supplementation