The only thing that matters in the context of evolution is passing on genes. In this respect, the genes which code for cattle are incredibly successful, largely

The only thing that matters in the context of evolution is passing on genes. In this respect, the genes which code for cattle are incredibly successful, largely due to human interference. It would significantly decrease the success of the species, and while the surviving cattle would be happier the individual's happiness is not relevant to the species' success, so long as breeding continues.