The local immune response in the mammary gland of the sow following infusion of a protein antigen.

A study was made of the local immune response in the udder of the sow following infusion of a soluble antigen. Four mammary glands of each of four pregnant sows were infused with ferritin prepartum. Samples of blood, colostrum, and milk were collected during the following lactation; animals were slaughtered and mammary tissue removed for immunohistology. Blood, colostrum, milk, and mammary tissues were similarly collected from nonimmunized (control) sows. Colostral and milk whey from immunized sows contained higher levels of immunoglobulins than whey from control sows. There was an increase in numbers of IgA-containing plasma cells and total lymphoid cells in mammary tissue of immunized sows compared with controls. The results suggested that the local immune response was at least as great in non-infused glands as infused glands of immunized sows.