This is the MOST chicks we have ever attempted brooding at once. We planned on 50, and ended up with 59! All survived which is really quite extraordinary.
We really needed another brooder for all these chicks, but we worked our way through. We started brooding in the house the first two weeks in large boxes. Started with two large boxes, and within a week, we needed to add another large box to handle their growth. We had the freezing temps with much cooler than typical end of February weather. We moved the chicks into the larger, four-foot square brooders during the first week of March. We had 29 chicks in one brooder and 30 chicks in the other brooder. This was fine at the start of the month, but now, two weeks in to March, it is no longer feasible. Typically, we can keep about 20 chicks in our brooders from week one to week six. Um.... yah, we really needed one more large brooder.
We decided, since 26 of the chicks will be leaving for their new homes in a couple of weeks, that we would divide them in half (based on their respective mini-flocks) to give them the added space for the next two weeks. This helps with their flock bonding experience by reducing the stress because they won't be crowded at all for the next two weeks. We placed the other 33 chicks into our larger six-foot square pull pen. Typically, we use this pen while pasturing and growing out our meat chickens. The chicks are small enough (at the moment) to have plenty of running, chasing around, and flying space in this larger pen for at least the next four to six weeks. We will be selling most of the rest of our chicks by that time as "left overs." We bought extra of all breeds to ensure that if any died or any were roosters, we would still have some of each breed available for the people we presold for this winter/spring.
We already have people interested in our 10+ week leftover pullets. So I'm fairly certain that we will be able to sell all those extras before spring is done.