Fertility of boar spermatozoa after freezing in the absence of seminal vesicular proteins.

A comparison of spermatozoa from intact boars and from boars without seminal vesicles, frozen in various diluents, was made to determine any differences in sperm quality after thawing and the conception rates of gilts. Sperm samples were frozen at -196 degrees C. 50 semen pellets were thawed after 1-3 weeks storage and assessed for postthaw motility at 37 degrees C. The percentage of eosinophilic spermatozoa was estimated. Random samples were assayed for L-aspartate 2-oxoglutarate aminotransferase activity. Enzyme release was measured. Gilts were inseminated 24 and 32 hours after 1st standing to a boar and gave slightly higher conception rates than those from intact animals although the differences were insignificant statistically. Overall conception rate was 35% for spermatozoa from boars without seminal vesicles and 29% for those who were intact. The diluents with 20% egg yolk and 2% casin with cholesterol and phosphatidyl serine provided significantly greater (p less than .05) cryoprotection than did that with 2% casein. In general, levels of enzyme release from the spermatozoa after thawing were 3 times those before freezing, indicating substantial membrane damage. It is suggested that the presence of seminal vesicular fluid at ejaculation has only a small effect on the fertilizing ability of spermatozoa frozen and thawed in suitable diluents.