Since 35 years ago boar semen has been frozen and used for artificial insemination (Al). However, fertility of cryopreserved porcine sperm has consistently been low as boar sperm are more sensitive to cellular stress imposed by changing osmotic balance, oxidative stress, low-temperature exposure, cryo-protectant intoxication etc. and are less able to compensate for these deficiencies at commercially applicable dosages. Additionally, differences in sperm freezability among individuals are well known. Here we review current advances on tests to screen sperm quality post-thaw, on ways of diminishing individual boar effects, on improvement of cryoprotection by novel extender components, on packaging and freezing protocols and freezing and thawing methods, and on the handling of sexed boar sperm. Major advances have been registered, which have improved cryo-survival and the capacity to process boar semen for commercial Al.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.