Well, thats a tough one. On the roo, you can look for spurs. Usually they show up when they are about 8 months old but this can vary. If they are really big, he could be over a year, if they were not removed. Also check the hens pelvic bones and see the width. If they are pliable, she is probably ready to lay, if the vent is also wide and moist, she is laying. the stress of moving could have caused them to stop laying. Check their overall condition and see if they have scars or how their feet look. Since they are new, I would also check for bugs or lice on them. Generally if they are old, they will still lay, just not as many. It is possible that they are also going through molt. Maybe post pics of them, especially combs and feet or spurs and maybe people can make a guess. How they were raised can also greatly impact how old they appear. It's really hard to say.