Hi, yeah I have found that bread does effect egg numbers not sure why other than it hasnt got the necessary nutrients etc in it to promote egg laying - i am able to get slightly stale bread frre from a bakers and so started to give it to my hens and found egg numbers dropping off after about a week -so stopped giving them the bread and stuck with layers pellets and egg numbers came back up. So now they only get an occasional bit of bread as a treat cos they do like it
I guess it must fill them up quickly like it does us humans? So I would stear clear if I were you,
hope this helps,
Nige.