I highly doubt this. The commercial brown egg layers are sex links and I have never heard of a case where someone ordered sexed day old White Leghorn chicks and got males instead of females or vice versa. And even if somehow some cockerels slipped through the cracks and ended up in battery cages there I doubt that there is even room for mating.Commercial egg producers probably sell the occasional fertile egg. Since 10-15% of sexed pullets are cockerels, there's probably roosters in battery cages...