829. Milk on Pesach
117:12 If one must feed chometz to a young child, he should take him to a non-Jew, who will feed him the chometz and who will be paid by the Jew later. The Jew should not feed the child the chometz himself unless the child is dangerously ill. If that's the case, then everything necessary is permitted; see chapters 92 and 192.
117:13 Some authorities permit milk from the cow of a non-Jew that is being fed chometz on Pesach, while others prohibit it. A scrupulous person should act stringently in this matter, especially in a place where the accepted practice is to prohibit such milk. (The Pri Megadim and others rule leniently in this matter; see Mishnah Brurah 448:33.)