Hi, is there a general guideline as to how much food one duck should be offered on average per day? I have mostly larger ducks, mallards, rouens etc. They all seem to be doing well, and I would like that to continue. All of my ducks are together so I don't know how much grain one duck eats alone, and was just wondering how much grain everyone offers per duck. I just want to make sure I am not over/under feeding. Thanks!!