Maybe some of the Brahman people can answer this question. How genetically different are the Zebu cattle from each other? You have the Brahman, Nellore, Indu-Brazil, Gyr, Guzzerat and so on. I know that they're considered different breeds but what is the difference in using one type of Bos indicus cattle over another? Phenotypically they are so similar, at least to my untrained eye, that I wonder if you used a Brahman bull on British cows would you get different results by using a Nellore or one of the other breeds?