What is a Sustained Motility Lifetime (SML™)?
The SML™ is defined as the time taken for the initial % of progressive motility to fall by one-half.
By selecting the most robust semen, we increase the likelihood that the sperm will survive the journey and complete fertilisation, leading to higher chances of pregnancy.
> 2hrs SML™ : Unlocking 8-10% higher conception rates
Research has shown that selecting semen based on SML™ (Sustained Motility Lifetime) data can significantly enhance herd fertility management. Studies in both the UK and Argentina have demonstrated that when the SML™ exceeds two hours, conception rates improve by an average of 8-10%. Integrating this advanced metric into breeding protocols empowers farmers to optimise conception outcomes, leading to more efficient herd reproduction and increased productivity.
How to use SML™ data?
To make the most of SML™ data in fertility plans, incorporating this marker provides deeper insight into the robustness of semen samples. This allows for strategic use to achieve optimal breeding outcomes. Here’s practical guidance for interpreting the SML values:
< 1 hour SML™
STOP
Indicates a lower duration of sustained motility. It is uncommon for the SML™ to be shorter than 1 hour, which may suggest that these samples could be compromised. It is advisable to:
- Conduct a tank audit
- Consult the supplier for guidance
1-2 hours SML™
CAUTION
Observed for around half of all sexed semen but rare for conventional semen. These samples need to be handled with care.
- Thaw each straw individually and inseminate immediately
- Best used in the most fertile cows and those under low reproductive pressure
- Choose a protocol that ensures to inseminate at the best time
> 2 hours SML™
GO
Demonstrates superior motility longevity, ideal for breeding cows with known fertility issues or to reach optimal conception outcomes.
- Inseminate with confidence following best practice
Improve on-farm nitrogen tank management and straw handling
As soon as semen arrives on farm we recommend a single straw from each batch to be tested for a period of 2 hours using a Dynescan and before the breeding season starts. We also recommend to take a single random straw from the nitrogen tank for re-testing during the breeding season.
Straw integrity is considered intact, when a Dynescan tests reproducible within 5%. If the deviation is greater, we recommend a tank audit to investigate potential transport, storage or handling issues.
Please ask Dyneval’s customer support to access our free tank audit tool.
The SML-certified Mark for Superior Breeding Potential
When choosing a bull for breeding, selecting one marked with SML™-certified Mark can make all the difference. Bulls that achieve a Sustained Motility Lifetime (SML) greater than 2 hours in 90% of all tested batches have proven their exceptional semen quality. This benchmark is a testament to their potential to boost conception rates and the performance of the herd.
So, when it’s time to purchase semen, look out for the SML™ “Improve” mark. This symbol isn’t just a stamp—it’s a promise that you’re investing in the future of your herd. It means you’re selecting the best for your farm, one step closer to better breeding outcomes, greater efficiency, and sustained growth.
Choose with confidence. Choose with SML™.
