OK, so, we've got 23 chickens (20 hens, 3 Roosters) and all of them - except 1 - have abruptly stopped laying eggs a week after we introduced 3 new birds (former show-birds, what a shock for them!).

No changes to food, no changes to bedding, plenty of calcium, good water...nothing but these three new birds - who have also stopped laying.

Suggestions?