HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Trounson, A. O. Articles by Jacobson, M. E. Search for Related Content PubMed PubMed Citation Articles by Trounson, A. O. Articles by Jacobson, M. E.

Frozen Storage and Transfer of Bovine Embryos

Alberta Livestock Transplants Ltd., RR 4, Site 12, Box 22, Calgary, Alberta

Abstract

Viability of bovine embryos after freezing and thawing was studied to determine the optimal stage of development for freezing and requirements for synchrony of recipient and embryo for successful transfer.

There was no significant difference in viability of frozen-thawed blastocysts obtained on day 7 and 8 after estrus providing they were enclosed in the zona pellucida. Pregnancy rates in recipients synchronous with the age of the embryo and those 1 day earlier in an estrous cycle were similar. Overall, 52% of frozen embryos continued normal development in vitro and 40% resulted in pregnancies when transferred to recipients. Fewer day 8 embryos which were free from the zona (hatched) developed in vitro after freezing (25%) and no pregnancies were obtained after 10 embryos were transferred to recipients.

Embryos obtained 11 to 13 days after estrus developed normally in vitro after exposure to 2M DMSO, seeding at –7 C and freezing to –20 C but survival was low after freezing to –110 C and storage at –196 C. Freezing rates between 1 and 2.4 C/min and concentrations of DMSO between 1.0 and 3.0 M had no marked effect on survival of embryos but there was a tendency for higher survival rates with rapid thawing.

It is concluded that the optimal stage for freezing bovine embryos is the blastocyst prior to hatching. For transfer after thawing, recipients may be either synchronous or a day earlier in an estrous cycle than the donor of the embryos.

¹ Present address: Monash University, Department of Obstetrics and Gynaecology, Queen Victoria Medical Centre, Melbourne 3000, Australia.

This article has been cited by other articles:

				G. Seidel Jr Superovulation and embryo transfer in cattle Science, January 23, 1981; 211(4480): 351 - 358. [Abstract] [PDF]