The study evaluated the relation between the oxidative stress index (OSI) in porcine seminal plasma (n = 76) with sperm resilience and in vivo fertility (farrowing rate and litter size of 3137 inseminated sows) of liquid-stored artificial insemination (AI) semen doses. The OSI was assessed as the ratio of advanced oxidation protein products to Trolox-equivalent antioxidant capacity, both measured using an automated analyzer. Sperm motility (computer-assisted sperm analyzer) and viability (flow cytometry) were evaluated in semen AI-doses at 0 and 72 h of storage at 17 °C. Sperm resilience was defined as the difference between storage intervals. Semen AI-doses were hierarchically clustered as having high, medium and low seminal OSI (p < 0.001) with those of low displaying higher resilience (p < 0.01). Boars were hierarchically clustered into two groups (p < 0.001) as having either positive or negative farrowing rate and litter size deviation; the negative one showing higher seminal OSI (p < 0.05). In sum, seminal OSI was negatively related to sperm motility and the in vivo fertility of liquid-stored boar semen AI-doses, with the receiver operating characteristic curve presenting seminal OSI as a good predictive biomarker of in vivo fertility of AI-boars (area under the curve: 0.815, p < 0.05).
Keywords: in vivo fertility; oxidative stress index; pig; seminal plasma; sperm quality.