DiGiorno Parmesan Cheese has NO ANIMAL RENNET in it! Yay! I just got off the phone with them. They said that it’s microbial rennet.
A note of explanation: The original Parmesan cheese comes from a region in Italy. In Italy, in order to name a cheese Parmesan (or the Italian equivalent, Parmigiano-Reggiano), it has to come from Parma and the surrounding region and it has to contain certain exact ingredients, including rennet made out of the insides of a calf’s stomach. See Wikipedia for a good explanation of this. The name is protected by law. In other countries, i.e. USA, cheeses may be named Parmesan, but it is to be understood that this is not the same cheese as the Italian original.
You better come into my kitchen, 'cause baby it's cold out there. 