My experience with Pied`s is YES you can cross with hereford,
but, be very selective about choosing your bull. I`m speaking in terms of calving ease,there are many to choose from. The bull i felt most comfortable with for calving is a bull named CAPTAIN (older bull) his calves would run upper 70`s to mid 80`s when i used him on hereford cows (1150 -1200 lb.) and Pied cattle in general have a good temperment. and i will add most calves sired by pied will have the patches around the eye. which is common in pieds.