I received my EE and BR chicks at the same time (hatched same day). According to Meyer's catalog the BR should grow slightly bigger than the EEs. Then I also got a few Cuckoo Maran chicks that were just a few days older. The EEs are growing. The Cuckoo Marans are REALLY growing but I know they will be bigger as adults so not worried about that. But the BR is just sort of staying the same. Her feathers aren't coming in as fast as the others. Her size isn't changing much. Her attitude is HUGE though so I don't think she is sick. Are BRs usually slow growers or is something wrong with her? She's eating and drinking and very active and outgoing.