To get maximum hybrid vigor, you need to cross one breed with totally unrelated breed to achieve the best of both animals.  Since Brahman are of the Bos indicus species, they naturally produce an exceptional first cross (F1) with Bos taurus breeds of  European or British origin. The resulting hybrid offspring is consistently superior. The calves also inherit many characteristics of its Brahman parent, such as drought tolerance, disease resistance, higher fertility and longevity.  It has been established and a known fact that the heterosis resulting from the crossing of the Brahman and any Bos taurus breed produces more milk that is higher in butterfat content than either of the two parents breeds. The female F1 are noted for weaning a calf with more weight per day of age than a straight bred counterpart. Pound for pound the Brahman F1 steers will make rapid, efficient gain in the feedlot resulting in a high yielding carcass with limited fat.  It is very popular,  particularly in southern parts of the United States, to cross a Hereford bull with  Brahman females. It stands to reason that this cross breed has the full benefit of hybrid vigor and is highly regarded by commercial cattlemen as being the perfect combination for producing replacement heifers or steers in the feedlot.