We have had our chickens for 4 years and me and my dad wanted to know what are the symptoms for when the chickens are going to stop lay eggs. (the adults)
They will slow production in the last couple of years, then they just stop. An older hen will not lay any more eggs once her supply to gone.
To quote Dr. Mike Petrik, DVM, MSc, The Chicken Vet As for her "lifetime" supply of eggs, she is born with the number of possible ova (yolks) already set. These number in the hundreds of thousands, and would take decades of daily egg production to deplete. A hen will stop laying because of old age (and therefore produce less eggs in her life) long before she would ever run out of ova to produce eggs.
Saw another post somewhere on here today that talked about chickens laying at 5 & 9 yrs old. This may not be the norm but not unheard of.