[Pepperpincushion]

We keep getting them  I have 6 hybrids who are all about 9 months old and with no health problems. But we are regularly getting rotten eggs - at least once or twice a week.
Is there any reason this could be happening?

[New shoot]

Are you sure they are not old eggs you are missing PP    Do your chicks lay in a nest box or on the floor of the house.  Sometimes eggs get covered with sawdust and only surface days later.

If you put your eggs into a jug of cold water and they stand on end instead of laying flat or very slightly tilted, they are old and you should chuck them.

[Pepperpincushion]

Well they did lay for a while under a bush and some of them were a week or 10 days old but I checked them all with the method you described and they seemed OK. But the last couple of weeks they have all come from the next box so none are more than a week old when opened and still getting the odd rotten one 

[New shoot]

Are you washing your eggs PP?  If so you remove the protective layer on them that prevents them getting infected by bacteria.  I wouldn't have thought a week was long enough to make them that bad, but its the only other thing I can think of.

The general rule of thumb is don't wash unless you have to, then use hot water and use the egg up straight away.  Cold water makes a freshly laid egg draw any surface guck through the shell 

[Pepperpincushion]

Are you washing your eggs PP?  If so you remove the protective layer on them that prevents them getting infected by bacteria.  I wouldn't have thought a week was long enough to make them that bad, but its the only other thing I can think of.

The general rule of thumb is don't wash unless you have to, then use hot water and use the egg up straight away.  Cold water makes a freshly laid egg draw any surface guck through the shell 

Ah, I have washed a few of them when they've been dirty (one or two of my girls still sometimes sleep in the nest box!) I had no idea you shouldn't do that. Thanks for the tip - I'll see if that sorts the problem.