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RSGI Genetics focus is on the production and distribution of genetic materials domestically and internationally; frozen semen, gender sex sorted semen and frozen embryos. RSGI is proud to be the first to bring a centralized semen catalog to the small ruminant industry, offering the best genetics in the US in one location.

RSGI prides itself in leading the way with high quality frozen semen products. Quality matters if you are the producer selling the genetics or the producer buying the genetics. We want each party to have success, and that starts with high quality frozen semen. The standards below have been set through collaboration with international leaders and science based data to provide the most reliable results.

RSGI Genetics

Frozen thawed semen minimum quality control standards

Gender Sorted Semen

How does it work?

This technology starts by taking a raw ejaculate from a Ram or Buck and separating 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 was designed to separate the semen into individual subpopulations of cells containing either X chromosome-bearing cells (female) or Y chromosome-bearing cells (male) based on the size difference between the two chromosomes.  Since the X chromosome is larger and contain slightly more genetic material than do Y chromosomes, they can be differentiated based on intensity of signals when the laser illuminates them.

The process involves putting semen into a media that contains a viable fluorescent dye that is attracted to genetic material. The more genetic material a cell contains, the more dye it absorbs. X chromosome-bearing cells absorb more dye than do Y chromosome-bearing cells. The semen is then run through a flow cytometer where the sperm pass single-file in front of a laser. The laser Illuminates each cell and, because of the viable dye, causes them to fluoresce. The amount of fluorescence determines whether the cell is carrying an X or Y chromosome.

The sorting machines fluidic jet produces between 60-70,000 droplets per second and applies a slight electric charge to each droplet containing the desired sperm cell based on the chromosome it is carrying. As the cells exit the machine, they pass between two differently charged field plates. The charge on the droplets that contain the sperm of interest reacts to these differently charged plates, one negative, one positive, which directs the droplets into the gender-appropriate vials.

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 in 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 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 RSGI 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.
  • Gender sorted semen requires specific thawing instruction for use.
  • LAI only is recommended while more trial work establishes ET protocols with Gender Sorted semen.

FAQ about Gender Sorts

What are the conception rates with Gender Sorted semen?

The research has shown that when using higher numbers of Gender Sorted sperm cells the conception rate can average 50%.

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

Small ruminant semen will be frozen at 8 million cells per pellet

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

The required minimum for LAI is 30 million cells per dose. RSGI packages 60 million cells per straw.

Why does Gender Sorted Semen have a lower cell concentration?

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.  

How far away from RSGI can I be and still haul in the day of my procedure?

We have breeders that haul to us the day of the procedure from as much as 5 hours away. RSGI has found that the “At Home” synchronizing of females for both ET and LAI work has several advantages IF the attention for detail is held to a high standard. The ability for donors, recips, and LAI females to leave and return to their own pen the same day has proven to be a very successful way to minimize stress during a very delicate time in the program.

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

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.

Can I sort semen that is already frozen?

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.

Why is the use limited to LAI?

To date, the research has centered around LAI only. Trials are ongoing to establish success in superstimulated females or donors.

What is the accuracy of the sorting process?

90% accuracy
This Technology would not be possible without the great partnership forged with RTI and Sexing Technologies.

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