Escherichia coli membrane‐derived oxygen‐reducing enzyme system (Oxyrase) protects bubaline spermatozoa during cryopreservation

The objective of this study was to determine the effectiveness of deoxygenation of semen extender using Escherichia coli membrane‐derived oxygen scavenger (Oxyrase) on post‐thaw quality of buffalo (Bubalus bubalis) spermatozoa. Sixteen semen ejaculates, four each from four bulls, were each divided into five equal fractions, diluted using Tris‐egg yolk extender supplemented with different concentrations of Oxyrase (0, 0.3, 0.6, 0.9, and 1.2 U/ml), designated as treatments T1, T2, T3, T4, and T5, respectively, and cryopreserved. Immediately after thawing, Oxyrase did not improve sperm kinetics and motility; however, it improved the keeping quality (significantly lower deterioration of post‐thaw sperm motility after incubation for 120 min) in T3. Further, T3 reduced (p