Open access publications in the SLU publication database

Abstract

Breeding companies want to use semen from bulls as soon as possible to take advantage of their desirable genetics. It takes several weeks for the sperm quality of young bulls to stabilize and for post-thaw sperm quality to become acceptable for artificial insemination. Seminal plasma proteins protect spermatozoa during cryopreservation; it may take some time for the seminal plasma protein profile to stabilize. The purpose of this study was to determine if the seminal plasma protein profile can be used as a marker of likely seminal maturity in young bulls. A comparison was made of the seminal plasma protein profile in the ejaculates of 10 bulls of 9-10 months old (Sample I), with the profiles from ejaculates taken from the same bulls at 13-16 months old (Sample II) using fast protein liquid chromatography. This is a method for separating classes of proteins according to their binding ability. The peak area and peak height of different classes of proteins did not differ significantly between the two samples for each bull, except for peak 5 (heparin-binding proteins) and total peak area (p<0.05). The heparinbinding protein peak height and area were significantly higher (p<0.05) in Sample II than in Sample I. In conclusion, levels of fertility associated heparin-binding proteins increase with age in young bulls and might serve as a biomarker of sperm maturity. .