I also advocate feeding concentrates to youngsters – generally through their 3rd year.
Maybe later, but that depends.
I have little pasture, so all my horses get hay 24/7/365. I am lucky that I have a supplier of very nice quality hay, both grass mix and straight alfalfa. I usually work it so my youngsters also get at least 5 lbs of the alfalfa
I don’t feed one “brand” – I mix my own. Ingredients vary for age of horse, etc., but for the average WB youngster age 2-3, it would be beet pulp, rolled oats, a Puriena product called “Country Acres Sweet”, which is a fortified COB in a pelleted form; 12% protein. Plus I add a fat product – either a rice bran pelleted product called “Satin Finish” or veg. oil. Lastly, a multi-vit formulated for this area. For the first 2 years I feed a joint/bone supplement called “OCD Pellets.”
Soak all in hot tap water. Stir & feed. Yummmmmm:D
Oh, yeah – forgot: a small handful of loose salt. Hot sauce to taste (kidding).
Amt. varies on horse/age/my eye, etc. Min is 3 lbs (total) max is usually 9 lbs (total) with up to 2+ cups of veg. oil.