Exploring the metabolome of seminal plasma in two different horse types: Light versus draft stallions

Abstract

The application of the ‘omics’ studies in the field of animal reproduction has been aimed at identifying novel biomarkers of fertility since the last few years. When assessing reproductive efficiency in horses, breed should also be taken into account as it can influence semen quality and fertility. Considering the growing interest in metabolomic analysis to evaluate male fertility, we aimed to investigate the metabolomic profile of seminal plasma in two different horse breeds. Twelve healthy stallions, n.6 American Quarter Horse (AQH) and n.6 Italian Draft Horse (IDH) stallions, regularly used for artificial insemination, were included in the study. Two semen collections, performed 30‐day apart, were considered for the assessment of semen parameters including gel‐free volume, spermatozoa (spz) concentration, spz progressive motility and seminal plasma analysis by 1H‐NMR.Semen characteristics differed between IDH and AQH (p < .05) as well as the first cycle conception rate that was higher in AQH than IDH (p = .001). Metabolomic analysis quantified 56 molecules in equine seminal plasma, with 11 metabolites showing different concentrations in IDH compared to AQH (p < .05).This study provided evidence of differences in seminal plasma metabolites' concentrations between studied horse types, highlighting specific metabolomic fingerprints characterizing AQH and IDH sperm.

Nuclear Magnetic Resonance (NMR) Metabolomics: Current Applications in Equine Health Assessment

“…However, they observed variations in the concentration levels of 18 out of these 28 metabolites. The authors also found that myo-inositol, isoleucine, and valine negatively correlated with progressive motility in donkeys, in agreement with the findings reported in horses by Bazzano et al [52].…”

“…Studies have been performed on seminal plasma in humans [58][59][60] and in different animal species [61][62][63][64]. Three of them [51][52][53] have focused on equine seminal plasma, providing interesting insights into the metabolites contained in this biofluid. A preliminary study performed by Magistrini et al [51] identified, by 1 H-NMR, metabolites defined as markers of sex gland secretions.…”

“…Finally, they performed a quantitative analysis to evaluate the concentration of the components, revealing that nine molecules were differently expressed by the ampulla and bulbourethral glands [51]. A more recent paper by Bazzano and colleagues [52] applied metabolomic analysis to seminal plasma in light and draft horse breeds. This study highlighted features of the metabolome of seminal plasma that differed in relation to horse breed.…”