I've always disgarded the fat after letting it cool in the refrig after it rises to the top. I suppose you could save it for stir fry or such. I know tallow and lard allow for a much higher cooking temp than any other oils. Also, foods fried in tallow or lard to not obsorb the fat the way foods fried with other oils, with the possible exception of coconut oil. Not that I fry foods, but it's interesting to note.
I have read that cooked fat is not digestable for dogs and cats, is this not correct?