My horse Rusty is an 11 year old Quarter Horse that looks more Thoroughbred than anything. My problem is that I cannot get him to gain weight. He has a smaller, longer frame to begin with, so that doesn't help. I feed him 2 scoops of Nutrena Safe Choice horse feed every morning and night, and he gets roughly half of a square bale a day. He's out with three other horses but is the alpha horse so food shouldn't be a problem. He's muscling nice and has filled out a bit since he got back in shape, but still does not gain weight. He has a jumping lesson once a week and then whatever intermittent riding I can fit in. You can feel his ribs and sometimes can see their outline. Here's a picture of him this past fall that you can look at.
I don't want people to think that I neglect my horse or anything because of his weight! What are some tips/suggestions/comments that you have?