Don't you also need to add to that the time it takes for chickens to get to egg-laying age? Which seems to be 4-5 months.

yes; and i did take it into account. I'm unwilling to share my methodology at this time, but the very little mainstream coverage of the cull last year was enough to piece together a timeline, and i'm sure a few people have, maybe even someone who isn't a complete nutterbutter.

In my estimation, the slaughter of chickens for disposal slowed down during the summer. Any reason why would be speculation i am unwilling to back up at this time.

Wash your hands if you handle livestock, people. and if you're around LOTS and cleaning up their poo, wear a respirator and eye protection. It's got what plants crave, but not humans!