He just added a bunch of roosters to that flock. When you change the pecking order and flock dynamics you can have a temporary drop in egg production. It doesn’t matter if that is adding or taking away roosters or hens. I wonder if that is what he is talking about?
I’d still like to see the video to see the context, but commercial egg laying flocks have no roosters. If roosters stimulated egg production, commercial egg laying flocks would have roosters.
Why do you want roosters? The only reason you need a rooster I if you want fertile eggs. Everything else is purely personal preference. What do you hope to gain by having roosters?
1 rooster per 10 hens is the most often quoted magic ratio for full sized chickens, 1 to 12 or 15 is more often...