Immunity to Escherichia coli in pigs. The role of milk in protective immunity to e. coli enteritis.

Milk whey from immunized sows increased the survival time of gnotobiotic piglets infected with Escherichia coli. The survival time of infected piglets fed milk whey from non-vaccinated sow's was the same as that of similar pigs fed condensed cow milk. The significance of milk antibodies in immune protection against E. coli enteritis is discussed and compared with that of absorbed colostral antibodies. From calculations presented it would appear that seven day old piglets receive approximately 1 g of gamma globulin daily from milk and that this is equal to the piglets total serum gamma globulin content. After seven days of age the gamma globulin content of piglet serum falls, whereas that of milk remains constant; milk is, therefore, potentially a major source of immunoglobulins with protective activity against E. coli associated enteritides.