FERTILITY OF LONG-TERM-STORED BOAR SEMEN - INFLUENCE OF EXTENDER (ANDROHEP AND KIEV), STORAGE TIME AND PLASMA DROPLETS IN THE SEMEN

Each of 359 ejaculates from 20 boars was diluted 1:10 either in Androhep or in Kiev medium and then compared for their fertilizing capacity on Days 2 and 4 (Trial I) or on Days 3 and 5 (Trial II) of storage. First services with 3100 sows and gilts were performed by professional AI technicians. Semen in the Androhep medium used on Day 4 produced higher pregnancy rates than inseminations with Kiev-diluted semen (77.8% vs. 68.5%, P less-than-or-equal-to 0.05). Pregnancy rates and average litter size were equal for inseminations on Day 2 and Day 4 with semen diluted in the Androhep medium. This was in contrast to Kiev-diluted semen. The average litter size decreased significantly with both extenders for Day 3 and Day 5 inseminations. There was a negative correlation between the percentage of spermatozoa with distal plasma droplets and both pregnancy rate and litter size with semen used on Days 2 and 4. The incidence of plasma droplets should not exceed 15% in ejaculates used for AI especially with stored semen.