Arachidonate 15-lipoxygenase and ubiquitin as fertility markers in boars

Abstract Accurate semen analysis is an important issue in the swine industry. We evaluated two candidate fertility marker proteins associated with sperm cytoplasmic droplet (CD), including 15-lipoxygenase (15-LOX) and ubiquitin (UBI) in a controlled single-sire artificial insemination (AI) trial. Ejaculates ( n  = 116) were collected from 18 fertile Large White boars monthly for 8 mo, and analyzed by semi-quantitative, densitometry-based Western blotting and flow cytometry with antibodies against 15-LOX and UBI. Data were correlated with farrowing rates (FR) and total numbers of piglets born (TNB) from 1754 AI services by 13 of 18 boars, and compared with a conventional microscopic semen analysis. In semi-quantitative Western blotting, both 15-LOX and UBI were correlated with seasonal changes in the percentage of normal ( r  = −0.38, P r  = −0.27, P r  = 0.35, P r  = 0.27, P r  = 0.31; P r  = 0.30; P r  = −0.38; P r  = −0.37; P r  = −0.33; P r  = −0.34; P