I didn't know you could tell fertility by cracking the egg open either. I saw a video produced by Purina Mills that had an expert mention it. I tried to research the topic and found it to be a bit confusing. Apparently, all eggs have a germinal disc which allows the egg to become fertilized. The difference in appearance of the disc tells whether it is fertile or not. I, however, have no idea what I'm looking at so I thought I'd get some expert opinions. With so many roosters, I figured it was probably fertile. I'm learning so much from you all....keep the info/advice coming!!!