The present study was conducted to clarify the effects of peptide Zn on IgA induction in the intestine or mammary glands of weanling and lactating mice. Weanling mice were fed rodent feed and 100 or 150 ppm peptide Zn-supplemented rodent feed for 14 or 21 days, and maternal mice were fed rodent feed or 150 ppm peptide Zn-supplemented rodent feed from 6.5 days postcoitus to 14 days postpartum. Supplemental peptide Zn had no effects on the numbers of IgA antibody-secreting cells (ASC) in the jejunum and ileum of weanling mice, but IgA concentrations in the jejunum tended to be lower in the 150 ppm peptide Zn-supplemented mice after 14 days of treatment. Supplemental peptide Zn tended to increase IgA ASC in the mammary glands and IgA concentrations in the jejunum of lactating mice and IgA concentrations in the feces of neonatal mice. These results indicate that supplementation of peptide Zn is slightly effective to enhance IgA induction in the mammary glands of lactating mice.
