Hi Paulso,
Yes, chickens do slow down on eggs as they age - as a rough rule of thumb, a 10% drop per year of age.
I don't keep Warrens and to be honest haven't much experience with them, however I believe they are a hybrid, bred to lay eggs - so they should do just that. I'm not sure how many eggs per year you should get from them but this is very dependant on the particular strain you have.
My guess is yes, they should be laying a few more eggs than you are getting unless the breeder of these birds hasn't paid that much attention to egg numbers within the breeder stock.
You can check a few things though...
1.
Red Mite - I know you have sprayed but these guys are notoriously hardy and may still be around. The easiest way to check for them is to wipe a white tissue along the bottom of the perch at night and look for blood 'smears' on the tissue. Egg numbers will drop if your birds are getting bitten by mites at night.
2. Feeding. Check what you are feeding your girls - here is an article on
Feeding Chickens - make sure they aren't getting too much corn - fat hens don't lay eggs.
3. Calcium and grit- needed to form egg shells and to grind down food - both are essential. Another article on
grit and oyster shell
They might have gone into moult but that's more likely a bit later on in the year. If they do moult you will soon have very scruffy looking birds and you will see feathers everywhere. A few feathers around the place is pretty normal.
Let us know how you get on anyway..
Tim.
