Sample preparation

Semen was collected two days a week from three boars each day, for 3 weeks. Semen samples were centrifuged at medium speed using E8 centrifuge (LW scientific, USA) for 20 min and seminal plasma was removed using transfer pipettes. The sperm pellet was then diluted (1:1; v/v) in one of two pre-warmed (32 °C) extenders: Androhep Plus (Minitube, USA) and Androhep Plus + 0.25% natural honey (as determined from exp. 1). Samples were transported approximately 12 miles to the laboratory for analysis and freezing. At the laboratory, diluted semen samples were cooled overnight in a semen cooler at 17 °C.