How long should it take a cow to become pregnant again after giving birth and running continuously with bull?

Answer 1

There are just too many factors at play here. First off, why is she being run continuously with the bull? Ideally the bull should be separated from the cow except during the time she needs to be bred or is ready to be bred. She should be bred 45 to 60 days after giving birth, a couple weeks later to time her cycles so that she calves around the same date. But if she's being run with the bull continuously she could have been bred much too soon after birth, like 20 to 30 days after giving birth, which is too soon because it doesn't give her the time to rest and allow her uterus to "involute" or return to its normal shape before conception.

So if I were you, unless there's a good reason that the bull should be kept with the cow 24/7/365, consider separating them for the reasons stated above.