When does chicken fertility start dropping?

[HonkABC]

When does the fertility of a hen or rooster start dropping? Thank you.

 

[Lady of McCamley]

I've heard a rooster is fertile until about 4 or 5 years of age. Ditto for hens. I find my older hens still fertile as in embryos develop but their shell quality deteriorates with age. I generally don't hatch from 4 to 5 years and beyond due to the more fragile shells break.

 

[HonkABC]

Does anyone else know anything about hen fertility?

 

[Perris]

There are few studies because most research on chickens is done by the commercial sector, and they are not interested in hens past 2 years old.

Some wild bird species are still fertile in their 20s, 30s, 40s and beyond.

I have 7 year olds who had offspring this year. No decline in their egg shell quality. They lay fewer eggs than they used to, but almost all their eggs are fertile.

My roos are younger - none over 3 currently. They don't thrive as well as hens when older, for social, flock dynamic reasons rather than biological ones (younger males make ex-doms' lives a misery).

 

[HonkABC]

Thank you!