Here's the description right off of Purina Mills' pamphlet:
Once your laying birds (and all adult birds including roosters, ducks, geese, and turkeys) reach 18 weeks of age, they will need Layena SunFresh Recipe to support egg laying. Natural and wholesome like the Start & Grow products, Layena contains high calcium levels to support eggshell formation while maintaining a healthy skeleton. In addition, Layena is fortified with manganese to enhance shell quality. High levels of xanthophyll from marigolds result in rich, yellow yolks, while the enhanced concentration of vitamin E provides for more robust immune protection.
I in no way support this product of endorse it's use, your money is your money, your choice is your choice, this is just the exact description in their promotional pamphlet that I have generously copied for your use.
It goes on to say:
Features . . . . . . . . . . . . . . . . Benefits
Natural Plant proteins For safe and happy birds (no animal proteins or fats)
Superior nutrition Great appearance and healthy eggs
Essential amino acids Strong healthy birds with lots of eggs
Exclusive level of marigold extract Rich yellow yolks
Key levels of calcium and manganese Strong shells with fewer cracks
Proprietary level of vitamin E Supports a healthy immune system
Certified Natural Your assurance of quality. Nutrition you can trust.
Hey, I'm not a vet nor a scientist, just relaying information, okay?
P.O. Box 66812
St. Louis, MO 63166-6812
(800) 227-8941
www.poultrynutrition.com