maybe the second batch was from a different hatchery, or she went to even cheaper feed....These hens were given to me to butcher for my dogs. They had mostly stopped laying, or had soft shell eggs. I'm sure they were on some cheep brand of feed and never out of their pen. This person had given me her last hens too. I had never butchered a bird, so I took them to a friend. She decided she wanted to keep them and as far as I know, they are still laying pretty well for her. Those girls were older birds, so I'm not sure why these did so much poorer.