From memory: there used to be a large 'farm' near Caistor in Lincolnshire, called Cherry Valley. Here they raised literally hundreds of ducks in very large sheds, like raising chickens. These were specially bred fast growing ducks, white feathered and usually fairly large. They were taken from the sheds to the factory where they were killed, de-feathered etc and packaged for supermarkets, restaurants etc. At the time that I'm thinking of they processed several hundred a day.
Some where left almost intact, just the guts removed, but beaks, and feet left on. These were referred to as Chinese or Hong Kong ducks, because they where destined for Chinese restaurants.
I worked there for a few weeks when I was a student, stacking the ducks prior to them going to be frozen. It was a dreadful job.