Our bulls have free choice round bales in front of them 24/7. They are made to clean up a bit by letting them run out for 24 hours. But in the bull lot there are anywhere from 3 to 7 bulls and we keep 3 round bales in there to minimize the fighting or one being a bully. The bulls are all ages, from 2 to 8 yrs, so want to make sure the younger ones can eat in peace. They get free choice mineral and a TM salt block so they don't get to slinging the mineral out of the feeder. A 5 gal bucket of pellets usually 15% once or twice a week unless it is really cold then maybe 3x a week. They do sometimes get a little fat, but I would rather a little fat than have them standing around being cold in the wet rainy/icy weather we often get. When they go to the cows in May/June they are on just grass and mineral by then. One thing I also like to see is if the bulls can get and stay in "very good" condition on just hay. The ones that don't often produce calves that don't.