Personally, I dont like Purina as a brand. Others will dissagree, but I have my reasons. I don't like to feed anything that isn't organic for one, pesticide reasons. And for two, I find that their feeds aren't always quality when we're talking about freshness. I've previously opened the bag before I did my research and found clumpy, old feed. I know others who have opened moldy bags, old bags, clumpy bags, and buggy bags. I have never had this issue since switching brands. I know its not uncommon to get old bags of feed, but I found that I got them more often when I was using Purina.
When talking about nutrition, supposedly Purina has pretty good numbers, but theres definitely some things I dont love.
Other than that, I don't think the average flock that is being kept for longevity should be fed layer. If your birds are pets, or you plan on keeping them for as long as you can, than the extra calcium in layer isn't good for them. Hens that are molting, brooding, older, younger, different breeds, over wintering, or not laying for one reason or another dont need the extra calcium. Or if you have a rooster of course. It will damage their kidneys overtime.
A better choice is an All Flock feed. Either that, or a Starter or Grower. I use Starter since I like the higher protein, and the brands that I like don't have an All Flock. It's basically the same thing.
When feeding an All Flock, starter or grower, you do have to give them free choice oyster shells so they can moderate their own calcium intake. They know how much they need and wont over eat it.
Good! That takes one thing off the list then.
I've had to switch to Kalmbach Non-GMO All Natural Flock Maker. Not Organic or local which isn't preferred, but I can get it on Chewy for $30 a bag. Its also no dust at all in the bag, and very fresh I've noticed, which I like. I hope to switch back to S&P when prices go down. The price might be different in your area or at a different seller as well, its worth checking out if you have a local feed store.
