Milk provides the newborn (neonate) with nutrients and an array of antimicrobial factors.  These are believed to help protect neonates from infection until their own immune system has developed.This section of the dairy science website reviews the properties and potential nutritional and industrial significance of the major antimicrobial systems of milk, with particular reference to the lactoperoxidase system.

The major antimicrobial proteins of milk are lysozyme, lactoferrin (Lf), lactoperoxidase (LP), and the immunoglobulins.  These have been discussed in summary form in the section on Inhibitors in Milk.  In some species minor proteins including a folate binding protein have been characterised.  While these ‘minor’ factors are not discussed here they can be important in certain situations.  Goat milk can have significant levels of folate binding protein and it is advisable to supplement goat milk with folic acid in addition to the normal ‘humanising’ compositional adjustments when used to feed babies.