ryno-
Brahman are known to be long lived. Many reasons, one being that they have hard long teeth. Compare the wood of a sweetgum to that of an oak. No comparison, right? Sweetgums grow fast and their wood is soft. Consequently the wood does not do well under wear and tear. What about the oak? Slower to deveop but much tougher when considering wear and tear. Well the bone quality/density whathavya of a Brahman will be slower to develop but longer lasting. This also can be said of the leg bones. Yes they will be heavier, but will also last longer. All while bearing in mind that there are good and bad in every breed.
So, to the point, any breed that has Brahman in it, should be longer lived. Such as Brangus. And that is just one of the reasons. Brangus "should" live longer than straight Bos Taurus if they are the right kind. Any that have genetic predisposition to problems such as bad udders, attitude issues, leg angle problems, hoof problems, .....are obviously not going to "last" as long on any ranch. And Brahman wont be easy keepers in northern climates.