The transfer of immunoglobins IgG, IgA and IgM from serum to colostrum and milk in the sow.

Abstract

The proportion of IgA, IgG and IgM in sow colostrum and milk that is derived from serum has been determined by measuring the transfer of (125)I-labelled immunoglobulin from serum. All colostral IgG and a high proportion of IgM are derived from serum as is 40 per cent of IgA. Thus it would appear that colostrum is not a true secretion since 90 per cent of its immunoglobulin content is of serum origin. In milk, however, 90 per cent of IgA and IgM and 70 per cent of IgG would appear to be locally produced in mammary tissue.