How Did Chicken Become Universal?

I didn't take any photos today. Jay did have an eye appointment. They check him yearly because he has glaucoma in his family. He had no signs of it. The eye place is next to the mall. So, we parked on the roof where we always do. We did pick up a few things at Walmart but didn't get a roast chicken today. 

I wonder how many chickens are slaughtered as food worldwide per day? There is hardly a place on earth where they're not eaten.