I saved 2 bred herefords. 1 has a bcs 2 i'm sure the other a 3 easy. the way the guys place looked he had no way of working the cattle so i'm sure he has'nt wormed in a while. both cows are up in age 5-8 years old my best guess. they are heavy bred so should i wait untell the calve or go ahead and worm now? i've never faced this, this time of year before. My concern stems from killing grubs and harming the cows or because their pregant and hurting the calve. any ideas are appreciated.