Everyone recognizes that some cows and cow families flush much more successfully than others. Just how big a role does this play?
It is significant. Superovulatory response is heritable to a large degree and animals from the same family line tend to respond similarly. But as you might imagine, this is “predictability” is diluted as you get further from the source. For example: It is reasonable to assume that a daughter of a great flush cow would respond similarly, but making similar assumptions about a great great granddaughter would be fantasy. And remember that there are two factors that must align for a super flush cow. She must superovulate well AND she must be able to fertilize that large batch of eggs. There are a lot of cows that can make 20 eggs, but far fewer make 20 embryos.
