I've been reading several posts that people give their chicks yogurt to aid in digestion. Should I be doing this with ours? Since yogurt doesn't actually need to be chewed do they need to have any grit with it? My chicks are on MannaPro Medicated Chick Starter Feed. I just want to give them the best start in life/growing as i can. What about using apple cider vinegar.... any thoughts?