Abstract

    Comparative studies of semen characteristics were carried out in 50% crossbred (Friesian X Sahiwal) and purebred Sahiwal young bulls maintained under sub-tropical conditions at Research Institute of Physiology of Animal Reproduction, Bhunikey and Semen Production Unit. Qadirabad, respectively. Semen was collected on weekly intervals for a period of one year. The semen characteristics (mean+SE), i.e., volume per ejaculate (ml), mass motility (0-5 score), individual motility of spermatozoa (%), dead and abnormal spermatozoa (%) were 5.62+0.14, 1.25+0.04, 50.50+0.93, 25.78+0.91 and 27.15+0.97, respectively in crossbred bulls. The corresponding values for these semen characteristics in Sahiwal bulls were 3.64+0.09, 1.36+0.04, 60.55+ 0.33, 27.73+0.87 and 15.41+0.86, respectively. These semen parameters differed significantly (P<0.05) between crossbred and Sahiwal bulls. It may be concluded from this study that the semen characteristics in crossbred (Friesian x Sahiwal) bulls ~'ere poorer than purebred Sahiwal bulls.

Key words: Semen characteristics, bulls, Sahiwal, crossbred.