Blanketing will help if your horse needs weight. They need the extra calories to keep warm, so if they are not as cold it will help. Also I have a harder keeper that needs more than just grass and hay in the winter. When I first got him he was way under weight (see photo in my album) and I actually added oil I think I was up to over a cup a day at one time but now am just using purina amplify (30% fat) and hoping I do not have to go back to the oil this winter, so far have not but if I need to I will. Oh and my horses get free choice hay, he just does not eat enough of it I guess. He also gets a couple of nice size flakes of alfalfa a day too.