For the last 3 years I have lost 4 to 6 calves every year. This year I have already lost 2. They are born fine, nursing and then 4 to 7 days old they die. Not coyotes oor buzzards because I have found the carcasses within a few days up to a week or two. This started when I bought 2 Santa Getrudis bulls 3 years ago. Never had this problem until I got these bulls. I have talked to 2 vets and they both say it is not the bulls. They say if the calves are born live it is something else. I can't think of anything else. I have around 60 head and have 8 calves that are fine and 2 that have died for no reason. Also, it hasn't been the same cow that has the calve that died, it is random momma cows that I have had for 8 to 10 years. I'm baffled. Thinking about swapping bulls. All I do and all I have ever done is worm my cattle. No vacs. Never have in the 40 years my dad and then I have. My 65 year old vet hasn't done anything but vaccinate for worms with ivomec. I'm baffled. It has to be the bulls passing something on.