Gender Sorting

Brief History

For many years the technology to separate the genders of semen has been available in the bovine industry. This highly sought-after technology has revolutionized the dairy cattle producer’s ability to more efficiently produce the next generation replacement heifers and not lose resources on the lower valued bull calves. The same has been true with the beef cattle industry having the ability to decide if they are selecting for show steers or purposely producing the next replacement heifer. Until now this technology has not been available to the small ruminant producers. The process of separating the genders is the same for large and small ruminants however the reproductive efficiency and insemination process is quite different. Given the small ruminant industry is a much smaller segment of the livestock industry the resources have lagged behind to support the research needed to determine the most effective breeding techniques for sheep and goats. After many years of research and development, the technology is ready for the small ruminant industry to take advantage of gender sorting.


How does it work?

This technology will take a raw ejaculate from a Ram or Buck and separate the male and the female sperm cells into individual samples of male and female specific cells. The dam (xx) will always contribute one of her two X chromosomes to her offspring. The sire (XY) however will donate either a Y chromosome or an X chromosome resulting in the offspring being male or female respectively. The gender sorting machine has the ability to sort the semen into individual samples containing sperm cells carrying the X chromosome (female) and/or sperm cells carrying a Y chromosome (male).

The process involves DNA staining the semen and then running it through a flow cytometer in a single cell stream. The sperm cells are electrically charged when struck by two laser beams and using this electrical charge they are deflected into X, Y and waste populations. The accuracy of this selection is considered to be ≥90%.

This sorting technology allows for immediate fresh use or frozen for future use. In the future, as research allows, we will be able to use sorted cells in IVF programs.


When can you use it?

Using gender sorted semen will give you the opportunity to ensure 90% of your lambs or kids being born is a specific window will be the gender you are hoping for. If your goal is to raise market animals for a specific show date or sales to a specific market, gender sorting can ensure you achieve it. If your goal is to produce as many daughters of a certain female family then gender sorting can ensure you achieve it. If you have a sire that produces higher quality males and/or females, you can now select specifically for that and eliminate the lower quality less desirable gender when using sorted semen.



  • Raw semen must meet minimum standards in order to be eligible to be sorted.
    • 80% progressive motile cells, Less than 10% primary and 15% secondary abnormal cells. Not more than a total of 20% total
  • All males will be housed at RSG to undergo clean out collection and evaluation in the days prior to sorting.
  • Ram semen will be frozen in pellets.
  • Buck semen will be frozen in straws.
  • All gender sorted semen will be only stored at RSG
  • All gender sorted semen will be inseminated by RSG veterinarians only. This is due to the delicate accuracy of handling and the sensitive nature of the thawing and usage of gender sorted semen
  • LAI only initially. Trial work is scheduled to finalize ET protocols.



Q: What are the conception rates with Gender Sorted semen.

A: The research has shown that when using higher numbers of Gender Sorted sperm cells the conception rate will be similar to what your program achieves with conventional frozen semen.


Q: What is the concentration of sperm cells in Gender Sorted Semen?

A: Small ruminant semen will be frozen at 8 million cells per pellet in comparison to the 2.1 Million used in cattle. This is because small ruminants are less reproductively efficient and require more cells to achieve higher pregnancy rates.


Q: What is the concentration of sperm cells in conventional frozen semen?

A: The required minimum for LAI is 30 million cells per dose. RSG packages 60 million cells per straw.


Q: Why does Gender Sorted Semen have a lower cell concentration?

A: Gender Sorting produces a sample of pure cells that are of the highest or best quality. All of the poor, dead or abnormal cells have been removed.  


Q: Why are rams frozen in pellets and bucks frozen in straws?

A: Research has shown that at this time the higher pregnancy rates are achieved when rams are frozen and thawed in the pellet form. Research is ongoing to begin freezing rams in straws. However, the data showed no difference results of straws verses pellets in goats.


Q: Can I sort semen that is already frozen?

A: No, this process is called reverse sorting and it is available in the cattle industry. Based on the higher number of sperm cells needed for small ruminants, we are not able to perform reverse sorting this time. It is possible down the road.


Q: Why is the use limited to LAI?

A: To date, the research has centered around LAI only. Trials are ongoing over the next 4 months to determine the potential with superstimulated females or donors. It is highly possible that we will have a protocol in place for donors by the 2019 season.


Q: What is the accuracy of the sorting process?

A: 90% accuracy


Pricing Breakdown 

Coming Soon!