I have two Simmental cows, both have had healthy calves years previous. In 2000, One cow had a healthy calf. The other cow had aborted her fetus before the second trimester. I then vaccinated with Fort Dodge, Triangle 9 & Type II BVD. Killed virus, Safe for all stages of pregnancy. I vaccinated the cows before I had them bred, I gave each two vaccinations, four weeks apart. I then, on the advice of my local veterinarian, gave the each a shot 6 months later to bring up their antibody titer. Now for the question. Both cows had full term calves. One had twins. The calves were born dead, they were jaundiced, and both cows retained their placenta. My question is, was it the vaccine that caused the deaths of the calves? And if so, how did it happen? The calves were not over do. The cows are on the same pasture they have been all their lives. I keep weeds in check. Nothing unusual or different in the care they were given during their pregnancy. If anyone has any ideas I would be very grateful.