Chicken semen cryopreservation: importance of cryoprotectants
Résumé
Sperm cryopreservation is an important strategy to conserve animal genetic diversity and transmit superior genetic background, facilitated by a non-invasive sampling and collection of large amounts of sperm. In chickens, various freezing protocols and cryoprotectants (CPAs) have been developed to freeze sperm, but each lab still debates and competes to disclose the most suitable freezing conditions. Many key points, such as semen donor selection, collection tips, diluent compositions, CPA selection, pre-freezing manipulation, semen packaging type, freezing and thawing rates, are all impactful to the efficiency of chicken sperm cryopreservation. Whereas glycerol is believed as the most efficient and the less toxic CPA, it also presents an unwanted contraceptive effect after insemination. Thus, one of the major developed strategies to conquer this issue is removing glycerol before insemination, but current protocols remain not efficient to completely abolish glycerol contraceptive effect. Novel methodologies will bring us a better understanding of the cellular and molecular mechanisms involved in sperm cryobiology to decipher the challenges of chicken sperm cryopreservation.