Affiliation:
1. Department of Biotechnology and Animal Science National Ilan University Yilan Taiwan, R.O.C.
Abstract
AbstractHigh sperm cryotolerance is crucial to the successful cryopreservation of boar sperm. Evaluating the cryotolerance of boar sperm by using a rapid and convenient technique can enhance the commercial viability of these sperm. This study investigated the correlation between sperm parameters for three sample subsets—fresh sperm, sperm with H2O2‐induced oxidative damage (hereinafter referred to as H2O2‐induced sperm), and frozen‐thawed sperm—to identify the potential of these correlations to predict cryotolerance. A total of 64 sperm samples were obtained from 64 Duroc boars. The sperm parameters of the three subsets, where the frozen‐thawed sperm were analysed at 30 or 180 min after thawing, were determined, and the coefficients of correlation between these parameters were calculated. The results indicated that H2O2‐induced oxidative stress resulted in decreases in various sperm parameters—including total motility (TM), viability (VIA), mitochondrial membrane potential (MMP), and live sperm with MMP (LMP)—but increased their coefficients of variation. Receiver operating characteristic (ROC) curve analysis revealed that the kinematic parameters of the H2O2‐induced sperm effectively predicted those of the frozen‐thawed boar sperm at 30 min after thawing; the corresponding area under the ROC curve (AUC) was 0.8667 for TM and 0.8733 for progressive motility in the H2O2‐induced sperm. For measurement at 180 min after thawing, the sperm membrane and mitochondrial parameters of the H2O2‐induced sperm effectively predicted the LMP of the frozen‐thawed boar sperm; the corresponding AUC was 0.8489 for VIA, 0.8289 for MMP, and 0.8444 for LMP. To our knowledge, this is the first study to directly establish a strong correlation between post‐thaw boar sperm quality and H2O2‐induced oxidative stress before freezing. Our proposed technique can serve as a valuable reference for the development of practical applications aimed at enhancing techniques for cryopreserving boar sperm.