Title
Cryopreservation of bison semen without exogenous protein in extender and its fertility potential in vitro and in vivo following fixed-time artificial insemination
Date Issued
01 August 2020
Access level
metadata only access
Resource Type
journal article
Author(s)
University of Saskatchewan
Publisher(s)
Elsevier Inc.
Abstract
Successful cryopreservation of bison semen is fundamental for restoration of genetic diversity in Canada's wood bison. Conventional bovine semen extenders contain animal products, such as egg yolk and milk, which are undesirable because of biosecurity risks and undefined composition. In this study, we examined the efficacy of an exogenous protein-free extender containing cholesterol-cyclodextrin complex (CC) to cryopreserve bison semen. The study also provided an opportunity to determine the effectiveness of different ovulation synchronization protocols for fixed-time artificial insemination in bison. Semen was collected from wood bison bulls via electroejaculation and cryopreserved in either Tris-egg yolk-glycerol (called ‘TEYG’) extender or pretreated with CC (2 mg/mL semen) and diluted in Tris-glycerol (collectively called ‘CC-TG’) extender. Post-thaw sperm motion characteristics and in vitro fertilization of cattle oocytes confirmed that CC alone without egg yolk protected bison sperm during cryopreservation process. In the first fertility trial, however, no pregnancy was obtained following fixed-time artificial insemination of bison cows with CC-TG extender. In a follow-up trial, low concentration of CC (1 mg/mL semen) resulted in better post-thaw sperm motion characteristics, fertility rate, and birth of live calves following fixed-time artificial insemination. Results showed that 1 mg CC/mL semen completely replaced egg yolk in bison semen extender. In addition, both follicular ablation and steroid treatment protocols provided ovulation synchrony to permit successful application of fixed-time artificial insemination in bison. This is the first report on the birth of live bison calves following fixed-time artificial insemination using semen cryopreserved in a defined extender.
Start page
156
End page
164
Volume
152
Language
English
OCDE Knowledge area
Ciencia animal, Ciencia de productos lácteos
BiotecnologÃa agrÃcola
Subjects
Scopus EID
2-s2.0-85084482623
PubMed ID
Source
Theriogenology
ISSN of the container
0093691X
Sponsor(s)
The authors are thankful to Dr. Miriam Cervantes and Eric Zwiefelhofer for their assistance with sample collection and animal handling. We thank the staff of the Native Hoofstock Centre at the University of Saskatchewan’s Livestock and Forage Centre of Excellence for animal management and handling. This work was supported by the Saskatchewan Agriculture Development Fund (Research Grant # 20160177 ); Agriculture and Agri-Food Canada (Research Grant # AGR-14227 ); and the Natural Sciences and Engineering Research Council of Canada , and the University of Saskatchewan .
Sources of information:
Directorio de Producción CientÃfica
Scopus