I have a 14.1hh 17yr old pony. She's looking a bit lean and I don't seem to be able to get weight on her. Currently she's on 1 scoop saracen chaff, 1/2 scoop pasture mix, 1 scoop sugarbeet, good splosh of vegetable oil and a scoop of riaflex AM and PM. Ad lib soaked hay and about 2/3 hours of...