People here say they do. I've never ate any. I knew an old guy that sold beef burger. He would buy bulls at the sale, take em home, use the clamp style castraters to avoid blood loss. Take their nuts off, feed em 30-60days and butcher them. Heck of alot of meat
A small producer I consult for had a mature bull that had him scared. I told him I would bring a couple mrkt cows over to help load the bull on the trailer. I got told NO! We weren't taking a chance on getting hurt. They just had the locker come out and butcher him. That bull had to weigh 2,400lbs plus. I don't know how much hamburger they got, but it was a lot.
They said it was good and lean. I know they sold the heck out of it.
I have had several pound cow buyers tell me that bull carcasses will absorb as many lbs of waters as it weighs. Then when they grind it they add some cow fat and there you go. Lots of cheap hamburger.