A new procedure for the cryopreservation of equine embryos.
Abstract: Early equine blastocysts and blastocysts were collected nonsurgically at six days post-ovulation. Thirty-two embryos were randomly assigned to a 2x2 factorial design. Factors were: 1) 0.5-ml straws or 1-ml glass ampules; and 2) plunging into liquid nitrogen (IN(2)) at -33 C or -38 C. Cryoprotectant, 10% glycerol in PBS plus 5% fetal calf serum (FCS) was added in two steps, 5% then 10%. Embryos were cooled at 4 C/min to -6 C and then seeded, 0.3 C/min to -30 or -35 C and 0.1 C/min to -33 or -38 C. Samples were thawed in 37 C water and glycerol removed in six steps, 10 min per step. Embryo quality and stage of development were evaluated prior to freezing, immediately post-thaw and after 24 h culture in Ham's F10 with 5% FCS. The mean post-thaw quality of embryos plunged at -33 C was superior (P<0.05) to that of embryos plunged at -38 C (2.0 vs 2.9). Embryos frozen in ampules and plunged at -38 C were of poorer quality (P<0.05) than those frozen in ampules and plunged at -33 C or frozen in straws and plunged at -33 C. After 24 h of culture, more embryos developed if frozen in straws compared to ampules, and plunging at -33 C resulted in higher quality embryos than plunging at -38 C. In Experiment 2, 23 embryos were packaged in straws and plunged at -33 C as described in Experiment 1. Six of the 23 surgically transferred frozen embryos were degenerate at thawing and the remaining 17 surgically transferred were via flank incision. Pregnancy rate at 50 days post-ovulation was 53% (nine of 17). Early blastocysts resulted in a higher (P<0.05) pregnancy rate (8 10 , 80%) than expanded blastocysts (1 7 , 14%).
Publication Date: 1985-07-01 PubMed ID: 16726058DOI: 10.1016/0093-691x(85)90211-0Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research focuses on a new cryopreservation procedure for equine embryos. It demonstrates that by using the correct freezing protocol, it is possible to improve the condition of frozen embryos and eventually, the pregnancy rates from transferred embryos.
Research Design and Methdology
- The researchers used early equine blastocysts and blastocysts which were extracted without the need for surgery six days post-ovulation.
- The embryos were randomly allotted into different groups to test two factors: whether they were stored in 0.5-ml straws or 1-ml glass ampules and whether they were plunged into liquid nitrogen at -33 C or -38 C.
- The cryoprotectant used was 10% glycerol in PBS supplemented with 5% fetal calf serum (FCS). This was added in two stages, 5% and then 10%.
- The embryos were cooled and exposed to different settings before being thawed. They were then evaluated for their quality and stage of development.
Results and Findings
- The results suggested a superior post-thaw quality of embryos plunged at -33 C compared to those plunged at -38 C.
- Embryos frozen in ampules and plunged at -38 C displayed poorer quality than those frozen in ampules and plunged at -33 C or frozen in straws and plunged at -33 C.
- Embryos that were frozen in straws and plunged at -33 C yielded a higher quantity of quality embryos post-culture.
- In the second experiment, a higher pregnancy rate was recorded when early blastocysts were used as compared to expanded blastocysts.
- Out of the 23 embryos frozen in straws and plunged at -33 C, six were degenerate upon thawing. The remaining 17 were transferred successfully, resulting in a pregnancy rate of 53%.
Conclusion
- The findings of the study suggest that the new cryopreservation technique is fruitful in preserving equine embryos.
- With the correct cooling method, storage medium, and temperature, it was demonstrated that better quality embryos post-thaw can be achieved, resulting in higher pregnancy rates.
Cite This Article
APA
Slade NP, Takeda T, Squires EL, Elsden RP, Seidel GE.
(1985).
A new procedure for the cryopreservation of equine embryos.
Theriogenology, 24(1), 45-58.
https://doi.org/10.1016/0093-691x(85)90211-0 Publication
Researcher Affiliations
- Animal Reproduction Laboratory Colorado State University Fort Collins, CO 80523 USA.
Citations
This article has been cited 7 times.- Dasiman R, Rahman NS, Othman S, Mustafa MF, Yusoff NJ, Jusoff WH, Rajikin MH, Froemming GR, Khan NA. Cytoskeletal alterations in different developmental stages of in vivo cryopreserved preimplantation murine embryos. Med Sci Monit Basic Res 2013 Oct 4;19:258-66.
- Raju GA, Prakash GJ, Krishna KM, Madan K. Vitrification of human early cavitating and deflated expanded blastocysts: clinical outcome of 474 cycles. J Assist Reprod Genet 2009 Sep-Oct;26(9-10):523-9.
- Barfield JP, McCue PM, Squires EL, Seidel GE Jr. Effect of dehydration prior to cryopreservation of large equine embryos. Cryobiology 2009 Aug;59(1):36-41.
- Sirois J, Betteridge KJ, Brault A. Transcervical embryo transfer in horses: an application in an equestrian teaching center. Can Vet J 1987 Dec;28(12):750-3.
- Poitras P, Guay P, Vaillancourt D, Zidane N, Bigras-Poulin M. In vitro viability of cryopreserved equine embryos following different freezing protocols. Can J Vet Res 1994 Oct;58(4):235-41.
- Foote RH. In vitro fertilization and embryo transfer in domestic animals: applications in animals and implications for humans. J In Vitro Fert Embryo Transf 1987 Apr;4(2):73-88.
- Duan W, Lopez MJ, Hicok K. Adult multipotent stromal cell cryopreservation: Pluses and pitfalls. Vet Surg 2018 Jan;47(1):19-29.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
