Is this normal?
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.
Bellow are the histograms showing the range and frequency of % progressive motility results, measured at the zeroth hour, for conventional (Figure 1) and sex-sorted semen (Figure 2) on-farm.
The data confirms that, as expected, processed semen tends to have a lower motility than fresh semen (usually higher than 60%). The latest data, shown in Figure 1a, shows conventional semen has an average value of 35.7% and a minimum value of 4.1% and a maximum value of 81.5% when measured over 251 straws. Further processing is required to produce sex-sorted semen and we find the average value is 13.4% with a minimum value of 1.8% and maximum value of 35.4% over 141 straws, as shown in Figure 1b, with sexing performed through both technologies that are commonly available.
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 and criteria that give rise to different results and therefore, it is vital to compare Dynescan measurements across the supply chain.
Customers are reminded that the presence of fat droplets in full fat milk extender or immobilised cells will reduce the absolute value of the % progressive motility measured with a Dynescan.
