Barley is a very common and cheap feed ingredient, because it can grow without irrigation on marginal land. It’s particularly good for ruminants that can digest it without feeling the bad effects of its sticky beta-glucans. Birds can be very badly affected by it. Since we can get local oats for about the same price and we prefer them for many reasons, we skip the barley. If you have birds, we suggest you do, too.
Some people sprout barley, and that works OK for birds. If you want to do it for fun, why not? Wheat sprouts equally well with no side effects, and around here it is cheaper, so we recommend that.
Here’s an article on feeding barley to poultry.