Update on sexed semen technology in cattle

摘要: The technology in current use for sexing sperm represents remarkable feats of engineering. These flow cytometer/cell sorters can make over 30 000 consecutive evaluations individual each second nozzle and sort the into three containers: X-sperm, Y-sperm unsexable plus dead sperm. Even at these speeds it is not economical to package standard numbers per inseminate. However, with excellent management, pregnancy rates cattle 2 million sexed insemination dose are about 80% those conventional semen normal doses. This lowered fertility, part due damage during sorting, extra cost limits applications that economically feasible. so, on order doses bovine annually United States. main application dairy heifers have heifer calves, either herd expansion or sale as replacements, often eventual export. Breeders purebred specific matings; thawing then frozen immediately using few resulting vitro fertilization done increasing frequency. Beef producers starting produce crossbred female replacements. Proprietary improvements procedures, implemented 2013, claimed improve fertility between 4 6 percentage points, 10%.