I have a 2001 TB gelding. He is by no mean skinny, I felt for ribs last weekend and he's got a nice amount of fat over them and a hay belly from winter. He can appear thin though because he has a bad topline. He's been off work since 2009 due to an SI injury but cleared to go back to work slowly now. I wondering though if there is something I can add to his diet to help or if its just a matter of building muscle. I will try to get pictures over the weekend when I go out.
For feed he is currently on free choice hay/water/mineral and gets half a waterbucket of beetpulp, oats and complete feed (mixed together it equals this amount)