Changes in pH of Boar Semen Extenders

1999 University of Nebraska-Lincoln Extension Swine Report. An experiment was conducted to examine the change in pH across time of five extenders (MR-A, VSP, BTS, Merck III and SpermAid). Type of extender and time of measurement affected (P < .01) the overall pH of liquid extender; however an interaction (P < .01) occurred between type of extender and time. BTS and MERCK III had a small increase in pH across time, MR-A and VSP had a linear increase in pH across time and SpermAid decreased in pH during the first 20 minutes before gradually increasing to a consistent level of pH at 50 minutes after preparation. Boar semen extenders do not have the same pattern of pH change across time. Semen should not be mixed with extender until a stable pH has been reached. In general, a liquid boar semen extender should be prepared 60 to 90 minutes prior to mixing with raw semen.