A healthy full-grown bird begins on day one. Provide a balanced starter diet to new chicks, based on their breed traits. Complete feeds are formulated to meet the needs of growing chicks and should comprise 90% of the diet. For chicks who will later lay eggs, select a feed that has 18 percent protein, like Purina® Start & Grow® Crumbles or Purina® Organic Starter-Grower. For meat birds and mixed flocks, choose a complete feed with 20 percent protein, like Purina® Flock Raiser® Crumbles. For laying hens, transition chicks onto a higher-calcium complete feed, such as Purina® Layena® Crumbles and Pellets or Purina® Organic Layer Crumbles and Pellets, when they begin laying eggs at age 18 to 20 weeks.