Temperature management during semen processing: Impact on boar sperm quality under laboratory and field conditions

Abstract Freshly collected boar spermatozoa are sensitive to a fast reduction in temperature because of lipid phase transition and phase separation processes. Temperature management during semen processing may determine the quality of stored samples. The aim of this study was to evaluate the influence of isothermic and hypothermic semen processing protocols on boar sperm quality under laboratory and field conditions. In the laboratory study, ejaculates (n = 12) were first diluted (1:1) with Beltsville Thawing Solution (BTS) at 32 °C, then processed either with isothermic (32 °C) or hypothermic (21 °C) BTS, stored at 17 °C, and assessed on days 1, 3, and 6. Temperature curves showed that 150 minutes after the first dilution, semen doses of both groups reached the same temperature. Two-step hypothermic processing resulted in lower sperm motility on days 1 and 6 (P