A friend of mine was recently in Eretz Yisrael. When he was here he visited many Gedolim to get brachas for his son who was born with a number of birth defects. He was by R' Chaim Kanevsky to a get a bracha and asked for eitzas in the matter. Among the things R' Chaim told him to do is learn a mesecta from Seder Kodshim (he said Zevachim b'frat) and to learn Hilchos Chalev (Yoreh De'ah Siman 64.)
If it would have been said by anyone else (A Chassidishe Rebbe, a Makubel, etc.) I wouldn't have been so interested to know why davka these 2 things. But since R' Chaim said it it's a bit more interesting. Perhaps there is some "makor" to this that the limud of these 2 things is a segulah for refuah?