I have always fed mine Starter and Grower from Ralston Purina until they start to lay (typically 17-20 weeks). Then I switch to the Evergreen Extra Egg 16. I have never had a problem and my birds are extremely healthy. Every couple of weeks, I add some vitamins to water for a day; ACV 1-2 times a week. Knock on wood, in three batches over several years, I have yet to lose a bird to illness.