Submitted to: International Congress on Animal Reproduction
Publication Type: Abstract Only
Publication Acceptance Date: April 3, 2000
Publication Date: N/A
Technical Abstract: This study focuses on achieving an optimum laser power for sorting X and Y spermatozoa to achieve optimum fertilization rate and embryo development. One aliquot of freshly ejaculated boar semen was diluted, stained with Hoechst 33342, and sorted with a MoFlo high speed sorter at one of two levels of laser power (125 and 25 mW). A control aliquot was diluted, but not stained (no-sort). Sperm were sorted as a complete population. Ovulation was controlled by gonadotropins; 44 hr after hCG, gilts were laparotomized and inseminated with 200,000 sperm (no-sort and sperm sorted at 25 or 125 mW) into the isthmus of both oviducts. Oviducts were flushed at slaughter 43 h after laparotomy, fixed in 4% paraformaldehyde, and stained with Texas Red-x phalloidin and Hoechst 33342. Confocal laser microscopy was used to visualize actin cytoskeleton and chromatin configuration. 426 potential embryos were flushed from oviducts; 311 were normal embryos. The proportion fertilized was decreased with 25 mW sorted sperm compared to no-sort or 125 mW sorted sperm (77.9 vs 96.3 and 96.2%). The incidence of polyspermy (11.1%) did not differ among treatments, but the proportion of fragmented embryos was greater for the 25 mW sort than the no-sort and 125 mW sperm sort (15.2 vs 4.5 and 7.2%, respectively). The proportion of normal embryos (80.4%) did not differ among treatments. However, the proportion of 3-4 cell and 5-10 cell normal embryos varied among treatments; with the 3-4 embryos greater in the 25 mW than in the no- sort and 125 mW sperm sort (78.2 vs 49.2 and 59%) and the 5-9 cell embryos less in the 25 mW than in the no-sort and 125 mW sperm sort (20 vs 49.6 and 35.1%). We conclude that the higher laser power (125 mW) is more effective for sorting swine sperm for use to produce offspring.