Headfry is right that it's the milk that can give hedgehogs tummy upsets, I don't think bread will do them any harm, especially if you put a dish of water out for them.

If you're lucky enough to have hedgehogs, it's worth being extra careful when it comes to strimming, lighting bonfires etc. Also if you have a pond, ensure there's chickenwire in one corner or similar so the hedgehogs can escape if they fall in.

I had a half barrel pond at my old house and found a drowned baby hedgehog in it - it was years ago and I still feel sad!!!