Page 119

Working Ranch April/May 2016

HOW THEY DO IT The sexed semen process, explained. The X chromosomes (determines female) in most animals contain more genetic material than Y chromosomes. In cattle, this difference is about four percent. The sorting process revolves around detecting this difference. After a semen sample passes an initial quality control check, it is combined with a media that nourishes and invigorates the sperm. The media also contains a fl uorescent dye that binds with genetic material. The more genetic material a sperm contains, the more dye it absorbs. The sample is then put through a sorting machine called a fl ow cytometer. The machine arranges the sperm in a single fi le line and then sends them past Source: Jim Hiney, Sexing Technologies a laser. The laser hits each sperm, causing the dye to fl uoresce. The amount of fl uorescence tells the fl ow cytometer whether the sperm is carrying an X or Y Chromosome. The fl ow cytometer then attaches a slight electric charge to the sperm cell based on the chromosome it carries. The larger commercial herds can benefi t from the sexed semen strategy by concentrating on building high quality replacement heifers. As the sperm exits the fl ow cytometer, they pass between two charged plates — one with a positive charge and one with a negative charge. The charge applied to the sperm cell and the charge of the plates combine to direct the sperm cell into the appropriate gender-specifi c vial. FLAXPHOTOS/SHUTTERSTOCK APRIL / MAY 2016 I WORKING RANCH I 119


Working Ranch April/May 2016
To see the actual publication please follow the link above