Thanks bnjrob - that's exactly the information I'm looking for! We have very similar issues with the heat of summer so we're in the same boat. I never thought of putting a light out there but I believe that would work. Or another thing we could do is breed them around September-October or so, that way we'd have a little better conditions for both laying and growing the chicks. I like the idea of examining while they're pullets and culling a few because you're right on the money that we'd never cull anything if we didn't - that's another thing I was thinking. I suppose we wouldn't need to consider fixed measurements for deciding to cull but rather relative to a standard bird in our flocks of the particular breed and age. I believe if done while they're laying, even though they're pullets, should be ok for determining who gets culled early. I'm guessing if one bird has say three finger width between pelvic arch and end of keel while most of the others have four or five then it's likely that same bird will be lag the others in year two.
Ok, yeah that helps quite a bit. Thanks again for the info - I feel a lot better now.
@bnjrob
gave great advice and most definitely knows a lot more than I do about selecting birds for breeding and culling. Thank you, @bnjrob
! I'm copying/pasting your comments in my 'great big book of everything chicken'.
Since I live only a little south from you, I would just like to emphasize that you really want to avoid hatching in the hottest months around here. I've encountered a number of issues with egg fertility in the summer months that I never experience during other times of the year, and I have a theory that their summer molt has something to do with it. Also, maintaining proper temperature and humidity in even the best incubators seems more challenging during monsoon season. I keep my incubator in the house in a climate controlled environment, but still have had repeated issues with summer hatches. And broody hens really struggle with their clutch in the summer. I know of a few people who's broody hens and chicks died from the heat.
I've now hatched every season here in AZ and two of my best hatches were in October, which ironically also resulted in some of my best growth rates. I did one hatch in January that resulted in a good hatch rate, but really slow growth rates. My March hatch results were dramatically improved by comparison.
Since "green" is so hard to come by around here most of the year, you may want to consider getting a small sprouting setup for supplemental feeding for your breeders. They're really inexpensive and easy to use and don't take up much space. I typically sprout sunflower, alfalfa, radish, wheat grass and broccoli sprouts during the cooler months along with growing kale in my garden for the chickens. They very much appreciate the nutrient rich "treats" and I've gotten better egg production from them as a result.