size of brooder for 45 birds?

[Minky]

I will be getting 20 heritage breeds and 25 meat birds, one week apart. The meat birds one week earlier.

Will I need two brooders? Trying to use just one heat lamp if possible....
How big do you think the brooder should be?

So far, Ive kept my 3 x 7 chest freezer box, but we've just moved so we have a lot of large boxes around.
I'm hoping by 5 weeks (June 1) they are in the chicken tractor/ yard play pen for most of the day while my adult flock free ranges around them, but it will be weather dependant here in southern Ontario.

 

[azygous]

With that many chicks, space will be playing a critical role right from the very start. You will probably need more than one heat lamp and more than one appliance box.

I would design it now and get all the kinks worked out so you don't lose any chicks due to overcrowding and being smothered or chicks unable to fit under the heat sources, thus dying from chilling.

Cardboard appliance boxes can be joined, taped together, and pass-throughs cut into the common walls. Then I would position a heat lamp at each end of the series of boxes. Calibrate the lamps to achieve temperature of around 90F under the lamps. Measure the area so you know how far out the warm spot covers so you know beforehand how many chicks can fit in the warm spot so there are no chicks shoved out into the cool zone. This is important for the first week when babies need a lot of heat. You may find you need a third lamp for the first two weeks.

Chicks double in size each week, so you'll need at least a square foot for each chick for the first few weeks and double that until they are big enough to move outside. Is a tractor going to be large enough to house 42 additional birds, or are you going to butcher at six weeks?

 

[The Moonshiner]

I would do separate brooders.
With that many chicks crowding and smothering is a concern. Those meat birds will out pace your heritage breeds in growth. They're gonna get way bigger way faster and putting the others at risk of getting trampled.
Just my opinion.

 

[AmazingRachel]

I would keep them separate and use the troughs they use at TSC for chicks. Square footage is 1 sq. ft. per chick.

 

[Minky]

Ok, thanks for the input---I think I will raise separately. We are planning on doing meat birds every year so I will have hubby build two chicken tractors/playpens. I would ideally have them all free range, if they would be warm enough!!!

I was told 8 weeks was about right for meat birds. I ordered males, so maybe they will be ready sooner?
Really not sure- Im a city girl.