I bought my horse, Barnabus, in early February. During the vet exam, he was measured at 916 lbs, and the vet told me that he should be around 1100 or so. At the end of March, the vet measured him again and he came out at 930 lbs. He gets grain twice a day, hay in the morning, and there's hay in the field for his nightly turnout. Other than a joint supplement (he's 15), he gets nothing else. Is 14 lbs of weight gain over 7 weeks a reasonable rate?