You just can’t beat the Cornish X, Cornish Cross, Cornish Rock, Broilers, whatever you call the hybrid meat chicks for feed to meat conversion. That’s the chickens you buy at the store. The down side is that you have to buy the chicks. It’s not practical for us to try to keep them and breed them.
They are so good at converting feed to meat that they are ready to butcher at 6 to 8 weeks. You have to butcher them at this age (unless you restrict their feed, which can get tricky) because they grow so fast their skeleton can’t keep up and it breaks down from all that weight or their heart just can’t pump enough blood to keep them going and they have a heart attack and die. If you control their feed some and butcher them when it is time, you should not have a lot of them breaking down and dying, but you may have a bit of a learning curve in getting that right.
The dual purpose cockerels do not do that good a job of converting feed to meat. You don’t have the breakdown problems with them that you do with the broilers but you have to feed them a lot longer. It costs a lot more in feed costs per pound of meat you get. Because they are older, the meat it more flavorful and can be tougher. You can handle the toughness issue by changing the way you cook them, use more moisture and lower heat. Some of us prefer the flavor of the dual purpose cockerels but for someone used to the chicken you buy at the store, the meat may taste a little strange.
If you try to hatch your own dual purpose chickens, half will be female. I eat every bird I hatch, male and female, but the females don’t have a lot of meat on them, even if you wait until they are older hens. There are only two of us so even a decent sized pullet gives us two meals, but many people want to talk about the males only when they talk meat. If you don’t eat the females you hatch, what are you going to do with them? Of course you can always just buy dual purpose males from a hatchery.
You cannot beat the efficiency of the Cornish Cross for meat but they are higher maintenance. You also have to butcher them when they are ready. The dual purpose cockerels cost more to feed but are require less maintenance. Some people consider them an inferior product but I personally like that flavor.