Coopchick, I think it is so strange that the three should have underdeveloped ovaries if they came from two different sources and were different breeds. I must be wrong in my thinking that such a problem would be genetic and unrelated to nutrition. I know poor nutrition can stunt development, but can't believe that yours were malnourished as chicks! I'm wondering if the lab guy could shed more light on that...what his opinion might be.
The rest of your flock, any chickens that came from the same age group as the 3 or 4 that are laying? Am wondering if there are more chickens who "will never lay" because of underdeveloped ovaries.
I'm sorry to be so persistent, its just that your experience was so similiar to mine that I am wondering how, despite our best efforts at providing the best for our chickens, that we find these things happening!
After hearing of your results, I went out and added another feeding station. It will have to go away after the snows come, but....
Totally freaks me out, I have to scrape out the dirt - it goes into a special compost dump where the chickens can't get to it.
I keep feed in metal garbage cans.