Crossbreeding of Holstein with some dairy cattle breeds and performance of crossbred cows.

Holstein is the most widely dairy cattle breeds in the world. Holstein dairy cattle milk yields were increased with genetic selection as a result increased inbreeding and health problems, decreased fertility, increased calving difficulty and health problems. Holstein dairy cattle farmers have begun searching for alternatives to overcome the problems. The use of other dairy cattle breeds for crossbreeding have contributed the solution for the problems. Often two-way crosses and three-way crosses were made in the rotational type to take advantage of heterosis. The crossbreed milk yields were decreased; however, animals had increased milk fat and protein yields, lower live weight, longer herd life, lower rate of stillbirth, less disease and lower health expenses which were advantages compared to pure Holstein. In our country, the cattle farmers have been crossbreeding Holstein with other dairy cattle breeds like as in other countries. In this study, the crossbreeding of dairy cattle breeds, the reasons of crossbreeds, crossbreeding applications and the results of this crossbreeding in different parts of the world were discussed. Key words: Dairy cattle, heterosis, milk yield, fertility