2,316. Milk From a Neveila's Stomach

Maachalos Assuros 4:19

Milk from the stomach of a neveila or a non-kosher animal is permitted like other bodily waste products. It is therefore permitted to use milk from the stomach of an animal slaughtered by a non-Jew or from the stomach of a non-kosher domesticated or wild animal in curdling cheese. The skin of the stomach, however, is like other intestines and prohibited.

Maachalos Assuros 4:20

A donkey's placenta* may be eaten because it is like waste, which is permitted. Some skin is like meat and one who eats an olive-sized portion is like one who eats an olive-sized portion of meat, assuming that he ate it while it was still soft.

*Literally "the skin that comes out opposite the face of a donkey" - see Rashi on Bechoros 7b, s.v. or haba k'neged p'nei chamor.