Poultry Brooder, grow Off Pens, and viewable expander below. -this can be the start of a very lucrative enterprise, producing approximately 48 chickens a month in a very limited space. Put approximately 48 chicks (day old) from a hatchery into the brooder, for warmth, feed, and water. After four weeks, move 24 birds into each grow off pen and put 48 new chicks in the brooder. 1 Poultry Brodoer and 2 Grow Pens. 36" x 30" x 9.75"