Applications and world-wide use of sexed semen in cattle

Successful sorting of sperm based on presence of the X-or Y-chromosome was first reported in the early 1980 ' s with the first live births reported in rabbits in 1988. Subsequent development of technological efficiencies resulted in commercialization of sex-sorted semen to cattle producers in 2003-2005. At product launch, low throughput dictated that reasonable prices to the producer could only be accomplished with extremely low sperm number dosages (2 x 106). Furthermore, conception rates were 70%-75% of those achieved by conventional unsorted product. Re-finements in sorting equipment have enhanced the number of sperm that can be sorted from a semen sample and (or) aliquot of time, which translates into reduced production costs, while modifications to other aspects of sperm processing and freezing have facilitated maintenance of a conception potential more similar to that of conventional semen. More recently, strategic use of sex-sorted semen coupled with genomic technologies to identify superior females to satisfy replacement female needs has, by default, led to identification of a population of dairy cows from which replacements are not desired, leading to a tremendous increase in use of beef semen in dairy herds. Though exact numbers are unavailable, estimates indicate sex-sorted semen is rapidly approaching 30% of the total AI market share in North America. Though the primary application of sex-sorted semen is to accelerate genetic progress while enhancing biosecurity through in-house production of replacement animals, numerous other potential applications are evolving or are under consideration.

Automated summary

The successful sorting of sperm based on the presence of the X or Y chromosome was first reported in the early 1980s, and the first live births were reported in rabbits in 1988. Technological advancements have led to the commercialization of sex-sorted semen for cattle producers in the early 2000s. Initially, low throughput limited the use of sex-sorted semen, resulting in lower conception rates compared to unsorted semen. However, improvements in sorting equipment and other aspects of sperm processing have increased the number of sorted sperm and improved conception potential. More recently, the strategic use of sex-sorted semen, coupled with genomic technologies, has led to an increase in the use of beef semen in dairy herds. Estimates suggest that sex-sorted semen is rapidly gaining a significant market share in North America. The primary application is to accelerate genetic progress and enhance biosecurity through in-house production of replacement animals, but other potential applications are also being explored.