Most of the eggs that are consumed are infertile. However would eating eggs from certain farms would increase kills of the male chickens (cockerels)? By killing, I mean brutally slaughtered by the use of lethal gas because of their little value. Does it happens on free-range also? 

If so, how do I know, and how to avoid that? Is there any extra label information which provides such information?

I'm interested mainly how it's in EU countries (however situation in U.S. can be also included).