Animal Science Department


Date of this Version

January 1999


Published in 1999 Nebraska Swine Report, compiled by Duane E. Reese, Associate Professor and Extension Swine Specialist, Department of Animal Science. Prepared by the staff in Animal Science and cooperating Departments for use in Extension, Teaching and Research programs. Published by Cooperative Extension Division, Agricultural Research Division, and Institute of Agriculture and Natural Resources at the University of Nebraska-Lincoln.
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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.