I don't know weights, but she is on a good hearty flake of alfafa twice a day, maybe more by some people's standards, we feed big flakes, and she gets a scoop of O+M, scoop of Timothy pellets, rice bran, beet pulp, and platinum performance supplement.
She wasn't always fat, as a younger horse she was harder to keep weight on, but as she has gotten older she keeps weight better. Also when she was younger I would switch between grass or oat hay to keep her calm. I know we add senior to everything above to feed underweight horses.
Troubled TB ~"A thorn by any other name will prick just as deep." @-'--,---