In this study, we propose a possible way of obtaining reproductive and respiratory syndrome virus (PRRSV) free offspring from genetically valuable lines of Přeštice black-pied boars com- ming from PRRSV-positive pig breeding herds with the use of artificial insemination (AI). The ejaculates were collected from 4 different lines of boars. Samples of fresh semen were not detected with the virus and 12 sows were inseminated. Blood samples of sows and their offspring were repeatedly tested for the virus but the results were negative. We managed in this way to maintain the endangered population of this breed and obtain PRRSV-free offspring.
In this study the quality of total RNA, isolated from fresh spermatozoa, was compared between boars with good and poor semen freezability (GSF and PSF, respectively). Semen from 3 boars with GSF exhibited significantly higher total motility, mitochondrial function, plasma membrane integrity and reduced lipid peroxidation compared with 3 boars with PSF after cryo- preservation. There were variations in the quality of RNA isolated from spermatozoa of boars with GSF and PSF. Boars with GSF exhibited mainly full-length, intact RNA, whereas substantial amounts of degraded RNA were detected in spermatozoa from boars with PSF. Further under- standing of the biological relevance of RNAs in sperm function is critical to improve the freezabil- ity of boar semen.