A neighbor threw some into my field a couple of weeks ago and my herd queen...who likely ate it ALL....got quite sick, had a big worm bloom, and dropped her milk production dramatically. And I was planning on milking her through.
I give free bread to my pigs and they won't eat it. I throw it out there anyways, figure it will be good compost.
The previous owners of my goats always fed their animals bred. She had horses and chickens in the same field as well as goats.
She fed several pounds of it every day to her animals and supposedly had no problems. Our doe absolutely loves it, but we giver a considerably smaller amount. A little bread will not hurt them, like less than a quarter of a loaf at a time.
As for your doe getting sick from the bread. Getting to much or any food the goats are not used to can make them sick.
any whole grain bread is fine for goats. you wouldn't want to over feed any item in your ration but in moderation its OK...White bread, the cheap stuff that is horrible even for us, should be saved for the pigs. Actually the starch and yeast is good for the active rumen, the extra carbohhydrate load needs to be adjusted by removing other ingredients from your ration...several producers that I know, add bread to rations as a cost saving, I tried it it but only had a limited supply so the trial didn't last long but I found that they weren't really that interested in eating much of it...again don't dump a whole truck load in the pasture and let them have at it....