The poultry in the picture are being destroyed, likely due to disease. They will be composted.
The chickens that you eat are not killed this way. They are stunned and then bled out. Known as meat birds or broilers, both the hens and roosters are processed for consumption at about 8 weeks. They grow very rapidly.
Layers, or chickens that produce eggs, are handled differently. They are sexed when hatched, and the males are destroyed since as Petey said they will not grow well enough to become broilers.
Boy, that’s just complicated. When I got big enough to swing an axe the folks put me in charge of killing chickens. No sex check. no weigh in. Just hack and next, But I had to split the heads between my dog and my Gramma. The dog had lunch and Gramma made chickenhead soup. Stayed that way until I left home, after which both the dog and Gramma died and my Mom never dressed another chicken. Gramma felt sorry for my dog——said he shouldn’t have to eat all those heads. I suspect the chickens still have a contract out on me ‘cause I converted so many of them to “fried.”
Thank you to everyone who helped give me an education in chicken farming. We learn a lot hanging out on these threads. Seems to me we should be trying to raise chickens to be healthier so we don’t have to kill so many, but I suppose we’d end up with eggs that cost $10 each and chicken meat that rivals the cost of Wagyu beef.