I have silkies & I keep the roos separated from the hens year around. I decided to hatch out some chicks & I put my best looking roo in with 5 of my best looking hens about a month ago. I left them together two weeks before I started gathering eggs. I have had those eggs under my broody silkie eggs since then. When I checked them last night they were all infertile! He has never been sick & appears to be healthy. I've heard that roos can go infertile, but he is only 3 years old & I don't think that is old for a roo. Is there anything I could put in his diet to boost his fertility? Is three old for a roo?