My horse is a 9 year old warmblood thoroughbred cross. She's getting pretty skinny in the back and hindqaurters. At the place where she's boarding the owners are giving her twice the amount of hay as their qaurter horses. So she should be getting plenty. She also is getting grain, flax, conola oil, and regenerx (so strengthen her bones). She was eating all her poop for a while too. The owners thing she is missing nutrients. What do you think would be the be the best way to help her gain weight for the winter?