It may be too late to help you on this emergency question but here is some information. In general breastmilk from a Jewish women who is keeping kosher would be prefered but in the case of threat to the health of the child there is MUCH leaway in Jewish Law as there is an overriding principle that a life threatening situation (and even a suspected one) overrides all the commandments with very few exceptions. The father should be asking this question of a competant rabbi to whom you can stress the health risks of other nutritive alternatives for this baby.