Domino and Prince have raw for breakfast every day, usually lambs' heart or beef chunks with an occasional chicken wing, and kibble for dinner on alternate days (the other dinners are Nature Diet).
They've been on this pattern for the past year and a bit and have had no problems.
Raw tripe is good for putting on weight, but be careful because it has quite a high proportion of fat, which is not always identifiable in the minced product.