Thank you very much for your help! I'm also wondering if there is any difference between layer feeds. In our area the feed stores carry Ranch Way, Nutrena, Land o Lakes, Purina, and Manna Pros Family Farm feeds.
They can get by with either but I would go with the 20% if the difference is price is not that much, the extra protien will help them continue to grow, and give them better feathers etc... If difference is outrageous, then 16 it is.
You'll find that which feed is best is a matter of opinion. I'm not familiar with most of the brands you mentioned, but I have used Purina and was disappointed. I have switched to Nutrena just this past week when I realized that of all the feeds I can buy here, it is the only one with animal protein. The others have soy, which I try to stay away from. Also, chickens were created to eat bugs and stuff so, I think, animal protein is more natural for them. imho.
I've been switching between Ranch Way and Purina with my flock. It just depends on which feed store I'm closest to when we need food.
I've been happy with the Purina Start & Grow. The layer feeds in the area range in price b/n $14.29 and $14.99 for a 50lb. bag, so it's not too huge of a price difference. I know the Ranch Way feed is at 20% protein and the Purina is 16%. I'm not too sure what the Land o Lakes and Nutrena are at though.
I have been buying the Nutrena because it is about $4.00 per bag cheaper, but the shell quality has diminished on my eggs. My birds have also been molting for about six weeks now too, which is kind of excessive.
If you check your labels you will see a difference in the ingredients. One of the most important vitamins animals need is D3 and the Nutrena mentions vitamin D but not specifically D3.