One of the few attempts that have been undertaken to improve dairy cattle productivity in India is crossbreeding the indigenous cattle (Bos indicus) with temperate (Bos taurus) breeds (Jersey and Holstein Friesian) with the aim of combining the high genetic potential of the temperate breeds with merits of adaptability and better disease resistance of the Indian cattle breeds. The increase in number of crossbred cows necessitated for producing crossbred Jersey (CBJY) and crossbred Holstein Friesian (CBHF) bulls for continuous supply of frozen semen throughout the country. But, there is inadequate information on the performance of CBJY and CBHF bulls even though such crossbred bulls are being used for decades for production of frozen semen straws. Hence, this book gives vital information about the status of semen production from exotic crossbred bulls in India, effect of genetic and non-genetic factors on semen production traits, association of scrotal circumference with semen production traits, estimation of genetic parameters, life time production of frozen semen straws, rejection rate of frozen semen, disposal of breeding bulls and early selection using Y-chromosome markers.