Novel Method for Assessing Boar Sperm Quality
LITHUANIA - Scientists at the Lithuanian Veterinary Academy and University of Helsinki have developed a simple fluorometer-based assay for boar semen used for artificial insemination.Several studies have been published where sperm plasma membrane integrity correlated to fertility. In this study published in Acta Veterinaria Scandinavica, Sutkeviciene of the Lithuanian Veterinary Academy and co-authors describe a simple fluorometer-based assay. This they used to monitor the fluorescence intensity of artificially membrane-ruptured spermatozoa with a fixed time staining with fluorescent DNA dyes.
Methods
Membrane-impermeable fluorescent dyes Hoechst 33258 ( H258) and Propidium iodide (PI) were used to measure the fluorescence of the nucleus in artificially membrane-ruptured spermatozoa, and membrane-permeable dye Hoechst 33342 (H342) was used to measure fluorescence of intact spermatozoa.
The concentration of spermatozoa in insemination doses varied from 31.2 × 106 to 50 × 106 per ml and the average value was 35 × 106 per ml.
Each boar was represented by three consecutive ejaculates, collected at weekly intervals. Non-return rate within 60 days of first insemination (NR %) and litter size (total number of piglets born) of multiparous farrowings were used as fertility measures.
Results
Sperm fluorescence intensity of H258 and H342, but not the fluorescence intensity of PI-stained spermatozoa correlated significantly with the litter size of multiparous farrowings, values being r=-0.68 (P<0.01) for H258, r=-0.69 (P<0.01) for H342 and r=-0.38, (P=0.11) for PI.
Conclusions
The increase in fluorescence values of membrane-ruptured H258 and unruptured H342-stained spermatozoa in boar AI doses can be associated with smaller litter size after AI.
This finding indicates that the fluorescence properties of the sperm nucleus could be used to select for AI doses with greater fertilising potential, say Sutkeviciene and co-authors.
Reference
Sutkeviciene N., V. Riskeviciene, A. Januskauskas, H. Zilinskas and M. Andersson. 2009. Assessment of sperm quality traits in relation to fertility in boar semen. Acta Veterinaria Scandinavica, 51:53 doi:10.1186/1751-0147-51-53
Further Reading
- | You can view the full report (as a provisional PDF version) by clicking here. |