Perspectives on cryopreservation, quality control, and artificial insemination of frozen-thawed boar sperm in a national repository

Authors: Purdy, Phil; KNOX, R. - UNIV. OF ILLINOIS; SINGLETON, W. - PURDUE UNIV.; SPENCER, K. - UNIV. OF ILLINOIS; Spiller, Scott; STEWART, T. - PURDUE UNIV.; THARP, N. - PURDUE UNIV.; Wilson, Carrie - Welsh; Blackburn, Harvey

Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/1/2008
Publication Date: 8/8/2008
Citation: Purdy, P.H., Knox, R., Singleton, W., Spencer, K., Spiller, S.F., Stewart, T., Tharp, N., Welsh, C.S., Blackburn, H.D. 2008. Perspectives on cryopreservation, quality control, and artificial insemination of frozen-thawed boar sperm in a national repository. Symposium Proceedings. Midwest Boar Stud Managers Conference, Saint Louis, MO August 7-8, 2008.

Interpretive Summary: The National Animal Germplasm Program (NAGP) is a repository for agricultural germplasm (sperm, eggs, embryos, blood, tissue, DNA) that has been collected, cryopreserved, and cataloged for the purpose of creating a living compilation of genetic resources. The repository is multipurpose and can be used to expand the genetic base of a breed, repopulate/recreate breeds or lines, for gene discovery, or for other research programs. What is essential in the creation of a collection of this type is to have an understanding of the post-thaw quality and fertility of the preserved samples. This enables management to make projections about the amount of material, by type, species, and breed needed to meet the aforementioned uses. Consequently, quality control throughout the cryopreservation process is extremely important to ensure populations can be reconstituted with predetermined fertility levels. During a typical year NAGP routinely freezes 30,000 straws (0.5 mL) of boar semen. Accordingly, quality control issues are important in our day to day operation. By analyzing the collection, handling, cryopreservation, and insemination processes we have adapted an approach that is beneficial for the repository and swine industry. We have therefore sought to answer the following questions: 1) What are the optimal conditions prior to freezing for transporting cooled, liquid samples so that they are in an optimal condition for cryopreservation?; and 2) Can we create better tools, or can we create a better understanding of the tools we have, to more thoroughly evaluate the pre-freeze and post-thaw quality of an ejaculate? By addressing these issues we endeavor to improve the cryopreservation and artificial insemination processes. The information presented in this manuscript is a compilation of numerous experiments that have been performed by NAGP personnel.

Technical Abstract: The National Animal Germplasm Program (NAGP) is a repository for agricultural germplasm (sperm, eggs, embryos, blood, tissue, DNA) that has been collected, cryopreserved, and cataloged for the purpose of creating a living compilation of genetic resources. The repository is multipurpose and can be used to expand the genetic base of a breed, repopulate/recreate breeds or lines, for gene discovery, or for other research programs. What is essential in the creation of a collection of this type is to have an understanding of the post-thaw quality and fertility of the preserved samples. This enables management to make projections about the amount of material, by type, species, and breed needed to meet the aforementioned uses. Consequently, quality control throughout the cryopreservation process is extremely important to ensure populations can be reconstituted with predetermined fertility levels. During a typical year NAGP routinely freezes 30,000 straws (0.5 mL) of boar semen. Accordingly, quality control issues are important in our day to day operation. By analyzing the collection, handling, cryopreservation, and insemination processes we have adapted an approach that is beneficial for the repository and swine industry. We have therefore sought to answer the following questions: 1) What are the optimal conditions prior to freezing for transporting cooled, liquid samples so that they are in an optimal condition for cryopreservation?; and 2) Can we create better tools, or can we create a better understanding of the tools we have, to more thoroughly evaluate the pre-freeze and post-thaw quality of an ejaculate? By addressing these issues we endeavor to improve the cryopreservation and artificial insemination processes. The information presented in this manuscript is a compilation of numerous experiments that have been performed by NAGP personnel.