Sorry if this is in the wrong area, please feel free to move if necessary. Anywho... I weighed one of my pullets today and she was only 4 pounds. They just turned 20 weeks, and have free access to food 24/7 plus free ranging and lots of treats including BOSS. I just switched from Starter to Layer as I got my first egg last week. They are Silver Laced Wyandottes. I thought they would be bigger by now? How do I fatten them up? How long before they are considered full-grown? Thanks!