I love rice bran, I really do. But it puts in weight very fast. When I bought my mare, she was about 200lbs underweight. I've had her for... hmm.. about 3 or 4 weeks now and she's put on a good 100lbs. AND she's a horse that works every day. So with a horse that isnt working and is already a little chunky, I probably wouldnt. Although as a treat once in a while that's fine, my broodmare gets it every so often as a nice treat. Because we all know SHE doesnt need any extra weight! Sometimes I wonder if she will fit through the stall door!