[sandyg]

I had 4 blackrock hens who laid eggs every day (I had them in 2008).   Last Autumn a fox got one of them and since then only one bird has been laying.   I have checked everything, diet, wormed them, regularly de-mite them, even tried the poultry spice but to no avail. 

How long are Blackrock chickens expected to lay for?   

[henamoured]

Would 2010 be their third summer then? If so, perhaps they have just got to the end of their eggs, particularly if they've laid every day for 2 years. 
Last resorts might be strict pellet only diet for a week or two, or course of antibiotics just in case it's an infection.

[Kazoo]

My black rocks are 4 and still lay like demons!

[hillfooter]

laying drops off about 15% in the second season and can be down to about 60% of peak in season three.  However performance after the first year usually is highly dependent on an individuals general health.  Good basic nutrition helps as henamoured says.  At this time of year older hens laying drops off a lot.  My youngsters (this years hatch) are still laying an egg a day but previous years hatches have dropped off to a dribble now as they go into moult.  Kazoo's hens are probably the exception rather than the rule though I've no idea how well demons lay like
HF

[joyfull]

blackrocks have been known to still lay the occasional egg at the age of 8 but it is only the occasional one. My blackrock is 3 and she is laying about 3 eggs a week.