Are those folks nuts? Usually we hear the rumor that you CANNOT have eggs unless you have a rooster, which we all know is dead wrong. But to say roosters interfere with the laying process, that's just crazy. In the natural order of things, roosters are needed to fertilize the hens so they lay eggs which will hatch into more chickens. Gotta have a rooster for fertile eggs.
Now, carrying that concept forward, if you have a rooster to fertilize the hens for viable eggs to hatch, and your hens go broody and sit on the eggs TO hatch them, then laying is interrupted by the incubation process, which takes 21 days. Then the hen still doesn't lay eggs whilst she is raising the chick, anywhere from four to eight weeks or so. Before she lays again.
But unless you've got a broody hen, they'll just lay their eggs and walk away from them, never sitting on them to incubate 'em to hatch.
Hatching chicks requires fertilized eggs and incubation for 21 days. The parts to the equation are: Rooster, broody hen (either the one that lays the egg or another hen that will set on 'em for her), FERTILE eggs, and time. Embryos do not develop without incubation. Eggs can be fertile as all get out but you won't get chicks unless the eggs are incubated, either naturally under a broody hen or via the use of an incubator.
We've established that roosters aren't necessary for laying, but they don't "really mess up the egg laying" unless the most important factor is present: a broody hen.
Some folks hope for broodies and never get one, some folks have broody hens they cherish, and others wish their broody hens would get over it, because there aren't any rooster to fertilize the eggs. Broody hens don't know the difference - they'll set on unfertilized eggs, golf balls, doorknobs, just about anything close to round. THAT interferes with laying: broodiness. Not roosters!
