Don't know if you've experienced the same thing. I started raising quail last Summer with a good pharaoh stock from JMF. They were doing great and I've had fairly successful hatch rate with their offspring. I set only eggs that are 14 to 15 g. Recently I got greedy and wanted to breed for larger birds, putting the largest hens with a huge roo in a cage. The last 2 batches I set eggs that were mostly 16g, a few 17g. I noticed a much lower hatch rate. Many of them died in shell because they could not get out. The last batch yielded 10 chicks, and I had to "help" 9 of them. They all seem healthy now. So I'm wondering if the egg size made the difference. Maybe bigger chicks just have a harder time in the cramp space and more difficult to pip out? The only other factor I could think of is the last 2 batches were winter hatching, whereas all of my previous hatches were in the warmer Summer and Fall months. We live in California so it doesn't get too cold, and I pick up the eggs every evening before they get too cold. Any insight? Maybe I should just be happy with the general stock from JMF and not worry too much about breeding for larger birds. Read somewhere that bigger birds tend to have more health issues. True in your experience?