Broiler chickens - what I didn't know

I recently finished reading Planet Chicken - an interesting enough read, if not a bit tediously drawn out in the second half. The author is not vegetarian and is happy to eat chicken, but wants to do it the right way so investigates where it comes from.

I knew a lot of this stuff already:

• broiler chickens are slaughtered at about 6-8 weeks old 
• many of them are lame and have leg problems due to their rapid growth
• they get ammonia burns from sitting in their excrement which is only cleaned up after they are removed for slaughter
• you can sometimes see these ammonia burns on the breasts and legs of whole chickens, but those with really bad burns get cut into chicken pieces

What I didn't know:

The chickens are not sexually mature when they are slaughtered, they are still babies. But, due to their breeding to rapidly gain weight these chickens would not survive much longer anyway due to the strain on their heart and their weakened bones.

The hens who lay the eggs from which these broilers hatch obviously have to live a lot longer in order to reach sexual maturity (at 18-20 weeks). And to keep them alive longer they have to limit their food to near starvation levels. The chickens are so hungry they eat droppings and drink excessive amounts of water. So water is also restricted so that their droppings aren't too wet, as that causes problems when the chicken has to live in it.

Doesn't that sound crazy? That an animal is bred in such a way that, unless starved, they would die before sexual maturation?

I also didn't know that the broiler breeding hens are almost featherless due to continual mating. Or that many are blind due to the high ammonia levels in their sheds. They produce about 140 chicks each before they are no longer productive enough to keep. Worn out breeders (10 months old) are no good for meat so go into canned soup, pies and baby food. The excess male chicks produced, 'hatchery waste', are minced alive.

I didn't know that the eggs were taken to be hatched in an incubator and once hatched the chicks get sucked up by a big tube and put into boxes to ship to the broiler farms. They actually put these newly hatched chicks in a box and send them in the mail! A newly hatched chick doesn't require food or water for a day or so - mother nature's way of allowing mother hen to stay put until all her eggs have hatched - very handy for the industry.

And I didn't know that even the 'happy farms' where the chickens are raised in a better environment still receive their chicks in the post from the same broiler breeders.