Quantitative and Qualitative Assessment of Sex Sorted Semen of Bos indicus and Bos taurus Breeds

Abstract Sexed semen can be used to produce offspring of the desired sex, and to produce replacement heifers from genetically superior cows. In the Indian dairy industry, this revolutionary technique is in its budding stage. The objective of this study was to assess quantitative and qualitative parameters of a) bovine cryopreserved sexed (for X sperm cells) (XS) spermatozoa produced through two different major commercial semen sorting techniques, and b) unsexed (US) spermatozoa of Bos indicus and Bos taurus breeds. By real-time PCR, it was found that the percentage of X chromosome bearing spermatozoa ranged from 62.88%±0.56 to 71.21±0.93 in US semen samples of four different cattle breeds: Holstein Friesian (HF), Jersey, Gir and Sahiwal. The corresponding values in semen sorted through flow cytometry technique ranged from 99.02% ±3.36 to 99.99%±4.56 in the above four cattle breeds; while the percentage of XS semen obtained through the decapitation of Y chromosome following sorting by flow cytometry ranged from 95.92% ±1.83 to 97.99%±2.74. Qualitatively, US sperm samples were found significantly (P<0.01) superior with high semen motility (65.98% ± 0.23), acrosomal integrity (75.28% ± 0.05), live spermatozoa (67.83% ± 0.42), and less sperm abnormalities (13.82% ± 0.02) than sexed semen samples. This is the first study to compare the quantitative and qualitative parameters of XS and US semen samples of major cattle breeds in India and adds significantly to the knowledge on semen sexing in Indian dairy industry.