I have never canned butter. How do you do it? I suspect that if it works for butter, it would work just as well for lard. Make a batch and see?
Let me tell you my granny owned a restaurant, and her cook always made the very best tasting pie crusts with lard.
Canning butter is not approved by the FDA. Neither is canning bacon, but I love to do both when I find a good sale! And everybody here is still alive and well. Let me look at my better Canning procedure for you and I will copy and paste it to you, probably early next week since I need to be off the computer for a while now due to some tendinitis and stuff...