I'm no expert on feeding cattle, I feed out a couple hundred head a year. I feed barley, mostly because I grow barley.  Barley makes a nice rotational crop "here"- it's cheap to grow, it gives me winter cover, we have a good straw market and I can get barley off early enough to plant beans and get yields equal or almost equal to full season yields.  I have been taking my barley off as high moisture (18-20%) and gringing it into an ag-bag.  Works real well for me.
      I have heard that barley will make a whiter fat, I can't really confirm that.  Barley is a touch higher in protien than corn.  Barley is a 48 lb bushel, remember that when comparing cost.  Barley grinds harder than corn, if you are running your grain thru a hammermill you will need a smaller screen and more patience than when grinding corn.  I think barley makes a good complimentary grain to add to a ration that includes corn if you have barley available at a competetive price.  Also, I would think it might be worth looking into just from a beef quality standpoint for your freezer beef market.