Is this normal?
Dynescan Measurements of Progressive Motility for Conventional and Sex-sorted Semen Samples
The Dynescan Semen Analyser is an excellent tool for measuring % progressive motility and mean speed over time. We recommend that continuous measurements for 2 hours are performed to assess the ability of spermatozoa to maintain motility during the aerobic to anaerobic transition, as experienced in vivo. If spermatozoa are unable to maintain progressive movement, then this is likely to impact conception rates. For examples, please see our ‘Are you Dyn-assured’ article.
As a reference, customers have asked us to share the range of initial progressive motility measurements, as measured on farm, to enable customers to compare their data for conventional (Figure 1a) and sex-sorted (Figure 1b) samples. For all data points shown, samples were prepared using 20µm depth, 4 channel microscope slides from Leja.
The data confirms that, as expected, processed semen tends to have lower motility than fresh semen (usually higher than 60%). Conventional semen has an average value of 37.6% and a minimum value of 10% and a maximum value of 70.7%, as shown in Figure 1a. Further processing is required to produce sex-sorted semen, and we find the average value is 15.2% with a minimum value of 6.7% and maximum value of 24.3% when measured on farm, as shown in Figure 1b.
If customers are concerned that straws may have deteriorated during transport or while stored on farm, we recommend they request Dynescan data from their supplier to compare batch data. Previous research performed by Dyneval on a batch split and held on 5 different farms showed a standard deviation of less than 5% – therefore we would not expect the difference to be larger when measurements have been performed with a Dynescan Semen Analyser. Laboratories operating computer-aided semen analyser (CASA) machines may use protocols that give rise to higher measurements of the percentage motility and therefore it is vital to compare like with like.