Found some lists. One doesn't list holly, one does, so I guess it just depends on the goat and/or how much they eat or if they have plenty of other safe browse to eat.
http://poisonousplants.ansci.cornell.edu/goatlist.html
https://fiascofarm.com/goats/poisonousplants.htm
http://poisonousplants.ansci.cornell.edu/goatlist.html
https://fiascofarm.com/goats/poisonousplants.htm