Cryopreservation of boar spermatozoa offers an effective means for long-term storage of important genetic material. This method eliminates the difficulty associated with transporting animals or fresh semen over long distances or extended periods of time. Successfully cryopre-served boar semen could improve pork production and its associated economic value internationally. However, current methods for cryopreservation are inadequate. To date, the use of cryopreserved boar semen often involves cumbersome processing procedures, and it yields low artificial insemination doses per ejaculate due to low cell survival, resulting in both low fecundity rates and litter sizes.
The current work is based upon the hypothesis that through a more thorough investigation of the fundamental cryobiological and biophysical properties of boar spermatozoa and how these properties are influenced during exposure to cryoprotectant agents (CPAs) and cooling and warming conditions, more optimal methods for boar semen cryopreservation can be developed. Prior studies with boar spermatozoa have determined such fundamental properties as the osmotically inactive cell fraction of the cell, the hydraulic conductivity (Lp), and the cells’ ability to regulate volume during preservation. By combining this information with knowledge of the cells’ ability to tolerate osmotically driven volume changes and their response to permeating CPAs, one can better predict optimal conditions for cooling and warming.