Publish date: 6.4.24
In the beef industry, the use of sexed semen increases every year. It is typically used to generate more replacement females or increase the total number of steers in a calf crop for feedlot purposes. With more people incorporating sexed semen as a reproductive management tool in their herds, our team has received additional questions about it. To help answer those questions, we developed this blog, where we dive into the most frequently asked questions and their answers.
How is sexed semen produced?
ABS’ sexed semen product is Sexcel® which is produced using cutting-edge laser technology that destroys the unwanted male or female sperm cells, depending on what the desired sex is. Female sperm cells contain about 4% more DNA than male sperm cells, and this small difference is what differentiates them from one another. Our technology detects this difference in DNA content to identify which sperm cells to destroy and which to keep.
In the end, straws of Sexcel contain both live viable sperm cells (predominantly the desired sex) and sperm cell fragments from the destroyed cells (predominantly the undesired sex). Have no fear though! Leaving the cell fragments in the straw does not interfere with product performance. We chose to leave them to avoid putting any more unnecessary stress on the viable sperm cells.
Are pregnancy rates lower with sexed vs. conventional semen?
It is likely that you will achieve lower pregnancy rates than you would with conventional semen when using sexed semen, so it is important to manage your expectations. You can expect a 90% relative conception rate compared to conventional, but keep in mind pregnancy rates of 75 to 85% of those with conventional semen have been reported in the past. Nevertheless, research is continuously being performed to enhance the sexing procedure and to improve estrus synchronization protocols for the use of sexed semen.
What is the best estrus synchronization protocol to use when incorporating sexed semen?
A group of Reproductive Specialists from universities across the US, known as the Beef Reproduction Task Force, has published a list of recommended protocols for use with sexed semen that is reviewed and updated yearly.
According to more recent research, pregnancy rates to fixed-time artificial insemination (TAI) with sexed semen have been increased through the use of the PG-7 7-Day CO-Synch + CIDR protocol in heifers (Oosthuizen et al., 2021) and with the 7&7 Synch protocol in cows (Andersen et al., 2021).
Is the timing of insemination different when breeding off of heats?
Yes, instead of artificially inseminating 12 hours after detecting a female in standing heat as you would with conventional semen, it is recommended that you breed 16 to 22 hours after the female is first detected in heat.
Do I need to do anything differently during the AI procedure itself?
Sexed semen is packaged in ¼ CC straws, so it is important to have a suitably sized AI gun. Either an AI gun specifically for ¼ cc straws or one for both ½ and ¼ CC straws, such as a Kombi gun, will work.
During the thawing procedure, straws should be thawed for a minimum of 30 seconds in a water bath heated to approximately 95 °F. It is also recommended that sexed semen be deposited in the body of the uterus within 10 minutes or less of thawing.
What are my options if I don’t want to use sexed semen on my entire herd?
A lot of people don’t breed their entire cow or heifer group to sexed semen. As mentioned above, it is always recommended to use sexed semen in females that show heat before AI to maximize your chances of establishing a pregnancy. With that in mind, there are a few ways that you could incorporate sexed semen in a proportion of your herd.
- Attach estrus detection patches to your cows or heifers when the last injection of prostaglandin is administered during your selected estrus synchronization protocol. At the time of TAI, you could read the patches and determine if the females have come into heat. If yes, you could AI them with sexed semen, and if no, you could AI them with conventional semen. This way, you are giving the sexed semen a greater chance of generating a pregnancy but can still generate some pregnancies with the conventional semen.
- You could also utilize a split-TAI estrus synchronization strategy, where you give females a second chance to come into heat and be bred with sexed semen. Females who have not come into heat by the first round of TAI are given extra time in which to come into heat. At the time of the second TAI, females that have come into heat could receive sexed semen and those that have still not come into heat could receive conventional semen. See the estrus synchronization protocol sheet for sexed semen for more information.
Key Points to Remember about Sexcel
- Sexcel is packaged in ¼ CC straws so make sure that you have the correct sized AI gun.
- Pregnancy rates are typically lower with sexed semen, so it’s important to manage your expectations.
- Use estrus synchronization protocols recommended by the Beef Reproduction Task Force for use with sexed semen.
- It is recommended that you use sexed semen in females that have come into heat.
Sexed semen is truly a powerful tool producers can use to not only change their calf crop but also improve their entire cow herd. With Sexcel, beef producers can be confident in the performance of the product because it combines the most advanced sexing technology available on the market today with superior fertility and the most profitable ABS genetics. To see our entire sexed genetic offering, head to Bull Search.
As a full-service genetics provider, we are here to help you every step of the way. Implementing sexed semen in your beef operation may seem complicated, but it does not have to be with a genetics partner who cares about your success and understands reproduction, synchronization, and fertility. To learn more about leveraging the power of Sexcel in your operation, contact your ABS Representative or complete the form below.
(608) 846 3721