I've been using Nutrena Legacy--which is formulated with endurance in mind.
My mules have done really well on it & about 2 years ago I switched all of
the horses on the farm over to it. (Used to feed Prime pellets to non-endurance
equines) It's a high energy feed, good for endurance, but not a 'hot' feed, so
good for the other horses too. And the beet pulp is already in it!! No, I
don't sell the stuff, or work for anyone who does. Just thought I'd mention it
because feeding is more interesting than some of the old debates that seem to
always crop up: 0 )