The rooster thing is true
Cobb-Vantress is a division of Tyson. They produce the grandparent stock. The chickens that make up the hens who produce the eggs to make into layers who then produce the eggs going into the broiler house. The males are bred as a separate line. For years, the top international male bird was the Peterson Male. The geneticist was from Korea working at the Peterson Industries breeder farm. After he died, the bird fell out of favor and the geneticist who took over wasn't all that good apparently. This gave Cobb and what used to be called Ross (Aviagen now) a chance to sell their males to the producers who didn't have their own genetics staff. Another early genetics firm was Arbor Acres (also in NWA and now part of Aviagen.) Of course, Tyson used Cobb hens, but also developed a line of male birds. I don't recall the exact numbers but there was a 400 bird, a 500 bird and maybe 18 months ago the went to a new bird line. There was complaints about vaccinating baby chicks for a gut protozoa. The "food police" of course didn't know one end of a chicken from the other but in an effort to respond to critics, Tyson et al have been trying to develop a chicken that is resistant to this coccidiosis disease. They introduced in about 2019 and growers promptly begin losing large numbers of their baby birds. After about 3 weeks or so, the bird builds a natural immunity for the most part. Anyway the new 600 series chicks or whatever the name was, was suffering high mortality due to coccidiosis.
A grower told me that this new bird was costing him about $40,000 a year or about $6,000 per flock. His field man admitted that he was probably about average. When you have invested $2,000,000 to get a $200,000 a year job, and you just sliced off $40k, well, it hurts.
I say all this to give you an idea how fragile the whole system is. When Lloyd Peterson was selling the Peterson Male worldwide, it was more popular overseas than here. The Ross/Cobb breeders were focusing upon maximizing white meat. Lloyd personally liked dark meat and couldn't understand that fried chicken was being displaced by chicken planks, chicken nuggets, and other processed white meat products. That's why you see an 8 lb. bird or "large broiler" occasionally in the store. I picked up some chicken recently and I thought it held a half dozen breasts when in fact it was 3 of the largest such pieces I've ever seen. I tried to bbq it but it was hopeless. I should have put them in a crockpot and make chicken dumplings or something. pitiful. I'd rather have the old 3# broiler any day.
In the end, Lloyd ran his company into the ground and died well into his 90s, and Peterson was ultimately sold to Simmons Foods but some part of the hatchery is still developing new chicken lines being run by his grandson. There is, in fact, a completely serviceable hatchery idle in Decatur, AR that could be put back in production and hatch baby birds. Simmons has a much bigger operation nearby so I suppose they don't need it. They just built a new processing plant on land once part of the Peterson Farms ranchland. One of the, if not, the largest such plant in the world.
Tyson's is a much larger firm than Simmons, which is still owned by a family, and have facilities all over. But they do independent research on these male and female lines to produce the chicken you eat. There are probably a dozen or more such outfits who do the genetics to develop these male lines separate from the egg producing female lines. They also work to produce birds expressing for the free-range chicken, egg producing chickens (which are smaller) etc. It's a complex business.