I just found out that the pasture I am renting this spring, that has a nice crick in it, also had 4 dead calves in it last year, 2 of which tested positive for black leg. Can I give my calves a black leg shot at birth, then the booster after 3 months when I haul them over there or is it too risky to give it at birth? Also, should the heifers that are calving have a booster for this or is it a one time shot thing? My vet.... who is retired and hasn't left the office for a decade claims one shot, no matter when, they will be fine. I don't want to take chances?!?