Abstract
A study has been made of the performance of crosses and backcrosses of Bos taurus and Bos indicus cattle using records covering a period of 15 years from the Experimental Station, Tanga. The gene combinations found in ½-bred animals were the most productive in this environment, and ¼-bred Bos taurus animals gave higher average daily yields of milk between calvings than those with ¾ taurus blood.