IMO, i wouldnt feed it on a 5day, maybe 7-8 for now, if you feed a seriously underweight animal, or human for that matter, the amount of food a healthy animal can eat, it can kill them just as easy as no food, so i would start on like a 7day for a month or so, then six for a few feedings, then to 5, that way you gradually introduce the idea of food being in the body, if you go from no food, to a bunch, it can become terribly sick, and just make it worse