The afore offered advice is spot on in their points they make. To the uninitiated, it may seem like you could do better making feed at home. You can't.
There are 2 primary reasons for that - cost and nutrition.
For 6 chickens, you would be buying grains and legumes in 50 lb. bags or even smaller quantities. Feed mills buy by the trainload.
You would be buying vitamin, mineral, amino acid and fat supplements by the pound (and you couldn't use them before they go bad). Feed mills buy those ingredients by the ton.
The economy of scale means it would be prohibitively expensive.
The other side is nutrition. When grains and legumes come into the mill, they are tested for nutrient concentration, moisture and the potential for fungus.
After the feed is ground, has all the supplements added, mixed and heat treated, the feed is then assayed to assure they have all the nutrients the chickens are known to need for their age in the correct ratios. You can't do that at home.
There is no way to provide that precise nutrition, based on well over a century of exhaustive research, with a home mix or for anywhere near the cost of a bag of feed.
Chickens' ancestors, the red jungle fowl, could glean all their nutrition from foraging in the wild.
But, for several thousand years, we have been selecting for greater production.
Jungle fowl produced perhaps 5 to 40 eggs a year. Modern chickens are expected to produce (depending on breed) between 100 and 300+ eggs a year that are twice the size of jungle fowl eggs. It takes optimal nutrition to achieve those numbers.
IMHO, the brand of feed doesn't matter a lot. As was said, buy fresh feed - especially since you are only feeding 6 birds. Less expensive feeds usually list terms like grain products or grain by-products as the primary ingredients while more expensive feeds will have things like corn, wheat, soybeans, etc. listed. Both still have the nutrition in the bag, the latter is using more expensive ingredients.
Just make sure you read the feeding instructions on the bag so you are buying the appropriate feed for the age and production level of your birds.
