Best Feed Brand? Supplements?

I have a few Bantam chickens, they "free range" tractor style and get scraps of veggies every day, my mom has chickens and feeds scratch, and crumbles, oyster shell and grit. My girls pick at the mixture, they eat the corn, some of the crumbles and leave the rest. Today I bought the Layena Plus Omega-3. What does everyone think of this brand? Any supplements I should be adding they may be missing out on? They get fresh garden veggies now green beans, peas, tomato scraps, fresh corn, cumbers, zuchinni, lima beans, carrots, etc. Not sure how I'll do this once winter hits though.