Looking for recommendations for an add-in vitamin/mineral supplement that will do the job without costing me a fortune; I've weaned my two off sweet senior feed and they are not getting the vitamins in the food i give them now ( renew gold, beet pulp and a combo of alfalfa and timothy pellets as well as grass hay(Burmuda)). A friend suggested a few that range from like 35.00 for a 10lb bucket to hundreds of dollars for a 50lb of a certain supplement. I'm used to the feed providing what they need so other than a salt block im not familiar with add in supplements for them. They do light work, ridden maybe 3 times a week on trails, and now get fed 2x a day to help keep weight on them with it being winter. Thanks in advance for the advice!!