Okay, I'll admit it...I'm a chicken expert, been raising them all my life.
Chickens will do fine in the heat of the desert as long as you keep fresh, cool water available at ALL times, and you will also need some kind of sun
cover or shade for them. Big trees work fine if they're big enough to throw off enough shade, otherwise you can make some kind of sun cover. It
doesn't have to be anything fancy, just something that will allow the chickens to get out of the direct sun.
When it is extremely hot, chickens will often stop laying or lay eggs more sporadically, but this is natural and there's nothing wrong with them.
They will start laying again regularly when the weather cools down a bit.
And a word to the wise, it's best to fence off your garden to keep the chickens out of it. Believe me, they will completely decimate your garden
over the course of just a few hours if given the chance.
Eggshells are a very good source of calcium and minerals for chickens, but do NOT feed the shells to your chickens if they bear any resemblance to the
actual eggshells. Either grind them or crush them up into very, very small pieces first. Otherwise, if you give them to the chickens while they
still look like eggshells, some of your chickens may turn into "egg eaters" and they will actually go into the nest and peck, break and eat any
newly laid eggs that they find. Once a chicken becomes an "egg eater," the only thing to do with it is either get rid of it or give it
away/segregate it and keep it for a pet only. Once an egg eater, always an egg eater.
You can also save all of your table scraps for your chickens, they will absolutely love it. Believe me, chickens will eat anything and everything.
The love fruit and vegetables, and yes, even cheese, scrambled eggs, noodles, rice and the like.
If you have any other specific questions, just ask away