It also depends on what kind of grain you feed. Make sure its not something packed with sugar and you shouldn't have a problem. Could ask your new barn owner if you can just provide your own bag of grain to use, and buy a ration balancer, like triple crown 30%, purina enrich 32...lots of them out there..its a feed balancer basically. Horse thinks its getting yummy grain, but its just getting the vitamins and minerals that it could be lacking from field/hay, its not packed with sugar, and you feed it in very small amounts. One 50lb bag for ~28 bucks, lasts me like 40-50 days. I feed ~1lb a day, whats recommended for my horses size...so yes it should last me 50 days but sometimes I probably add a tiny bit too much when I'm rushing..not really that big of a deal though.