I bought a bag of oxbow timothy hay and inside was a little pamphlet advertising the importance of variety in grass hays for a piggies diet. Recently my vet had also recommended trying some orchard grass in my pig's diet on top of the timothy hay that they always get, and i passed at the time but then later I bought some orchard grass at the store and mixed some in with their timothy hay and they already seem to love it! Is it very important to provide a variety instead of just timothy? If so, could it upset their tums and should it be introduced slowly since they've never had it?