Register      Login
Reproduction, Fertility and Development Reproduction, Fertility and Development Society
Vertebrate reproductive science and technology
RESEARCH ARTICLE

Assisted reproduction techniques in the horse

Katrin Hinrichs
+ Author Affiliations
- Author Affiliations

Departments of Veterinary Physiology and Pharmacology and Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA. Email: khinrichs@cvm.tamu.edu

Reproduction, Fertility and Development 25(1) 80-93 https://doi.org/10.1071/RD12263
Published: 4 December 2012

Abstract

This paper reviews current equine assisted reproduction techniques. Embryo transfer is the most common equine ART, but is still limited by the inability to superovulate mares effectively. Immature oocytes may be recovered by transvaginal ultrasound-guided aspiration of immature follicles, or from ovaries postmortem, and can be effectively matured in vitro. Notably, the in vivo-matured oocyte may be easily recovered from the stimulated preovulatory follicle. Standard IVF is still not repeatable in the horse; however, embryos and foals can be produced by surgical transfer of mature oocytes to the oviducts of inseminated recipient mares or via intracytoplasmic sperm injection (ICSI). Currently, ICSI and in vitro embryo culture are routinely performed by only a few laboratories, but reported blastocyst development rates approach those found after bovine IVF (i.e. 25%–35%). Nuclear transfer can be relatively efficient (up to 26% live foal rate per transferred embryo), but few laboratories are working in this area. Equine blastocysts may be biopsied via micromanipulation, with normal pregnancy rates after biopsy, and accurate genetic analysis. Equine expanded blastocysts may be vitrified after collapsing them via micromanipulation, with normal pregnancy rates after warming and transfer. Many of these recently developed techniques are now in clinical use.

Additional keywords: embryo, embryo transfer, equine, fertilisation, follicle, oocyte, preimplantation genetic diagnosis.


References

Albihn, A., Waelchli, R. O., Samper, J., Oriol, J. G., Croy, B. A., and Betteridge, K. J. (2003). Production of capsular material by equine trophoblast transplanted into immunodeficient mice. Reproduction 125, 855–863.
Production of capsular material by equine trophoblast transplanted into immunodeficient mice.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXltFeltLY%3D&md5=3f5aa45e9a58a9163ae69764bde7d19cCAS |

Alm, H., and Hinrichs, K. (1996). Effect of cycloheximide on nuclear maturation of horse oocytes and its relation to initial cumulus morphology. J. Reprod. Fertil. 107, 215–220.
Effect of cycloheximide on nuclear maturation of horse oocytes and its relation to initial cumulus morphology.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XmsFGgtr8%3D&md5=32ab74015b16b224fa287ecc38845774CAS |

Alm, H., Torner, H., Becker, F., Kanitz, W., and Hinrichs, K. (1997). Comparison of different methods for recovery of horse oocytes. Equine Vet. J. Suppl. 25, 47–50.

Alm, H., Torner, H., Blottner, S., Nürnberg, G., and Kanitz, W. (2001). Effect of sperm cryopreservation and treatment with calcium ionophore or heparin on in vitro fertilization of horse oocytes. Theriogenology 56, 817–829.
Effect of sperm cryopreservation and treatment with calcium ionophore or heparin on in vitro fertilization of horse oocytes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXnvF2mtL8%3D&md5=09a4cd39b78e96fd9b3c2fbd7a4d4657CAS |

Barfield, J. P., McCue, P. M., Squires, E. L., and Seidel, G. E. (2009). Effect of dehydration prior to cryopreservation of large equine embryos. Cryobiology 59, 36–41.
Effect of dehydration prior to cryopreservation of large equine embryos.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD1MvmtFSgug%3D%3D&md5=2233bb29c4d125e08721d27c3b3350bcCAS |

Bass, L. D., Denniston, D. J., Maclellan, L. J., McCue, P. M., Seidel, G. E., and Squires, E. L. (2004). Methanol as a cryoprotectant for equine embryos. Theriogenology 62, 1153–1159.
Methanol as a cryoprotectant for equine embryos.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXmt1Kmsrw%3D&md5=aab78729329c6d983816b0ef52d661f9CAS |

Bézard, J. (1992). In vitro fertilization in the mare. In ‘Proceedings of the International Scientific Conference on Biotechnics in Horse Reproduction’. (Ed. K. Kosiniak.) p. 21. [Abstract] (Agricultural University in Krakow: Krakow.)

Bézard, J., Magistrini, M., Duchamp, G., and Palmer, E. (1989). Chronology of equine fertilisation and embryonic development in vivo and in vitro. Equine Vet. J. Suppl. 8, 105–110.

Bézard, J., Mekarska, A., Goudet, G., Duchamp, G., and Palmer, E. (1997). Timing of in vivo maturation of equine preovulatory oocytes and competence for in vitro maturation of immature oocytes collected simultaneously. Equine Vet. J. Suppl. 25, 33–37.

Blondin, P., Coenen, K., Guilbault, L. A., and Sirard, M. A. (1997). In vitro production of bovine embryos: developmental competence is acquired before maturation. Theriogenology 47, 1061–1075.
In vitro production of bovine embryos: developmental competence is acquired before maturation.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD28zgtVyjug%3D%3D&md5=594dec2dc668cea1bbf75d6e29221bb1CAS |

Bøgh, I. B., Bézard, J., Duchamp, G., Baltsen, M., Gérard, N., Daels, P., and Greve, T. (2002). Pure preovulatory follicular fluid promotes in vitro maturation of in vivo aspirated equine oocytes. Theriogenology 57, 1765–1779.
Pure preovulatory follicular fluid promotes in vitro maturation of in vivo aspirated equine oocytes.Crossref | GoogleScholarGoogle Scholar |

Brück, I., Raun, K., Synnestvedt, B., and Greve, T. (1992). Follicle aspiration in the mare using a transvaginal ultrasound-guided technique. Equine Vet. J. 24, 58–59.
Follicle aspiration in the mare using a transvaginal ultrasound-guided technique.Crossref | GoogleScholarGoogle Scholar |

Carmo, M. T., Losinno, L., Aguilar, J. J., Aroujo, G. H. M., and Alvarenga, M. A. (2006). Oocyte transport to the oviduct of superovulated mares. Anim. Reprod. Sci. 94, 337–339.
Oocyte transport to the oviduct of superovulated mares.Crossref | GoogleScholarGoogle Scholar |

Carnevale, E. M., and Ginther, O. J. (1993). Use of a linear ultrasonic transducer for the transvaginal aspiration and transfer of oocytes in the mare. J. Equine Vet. Sci. 13, 331–333.
Use of a linear ultrasonic transducer for the transvaginal aspiration and transfer of oocytes in the mare.Crossref | GoogleScholarGoogle Scholar |

Carnevale, E. M., and Ginther, O. J. (1995). Defective oocytes as a cause of subfertility in old mares. Biol. Reprod. Monogr. 1, 209–214.

Carnevale, E. M., Maclellan, L. J., Coutinho da Silva, M. A., Scott, T. J., and Squires, E. L. (2000). Comparison of culture and insemination techniques for equine oocyte transfer. Theriogenology 54, 981–987.
Comparison of culture and insemination techniques for equine oocyte transfer.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3M%2Fot1Cisw%3D%3D&md5=bebf269f56ba2368b6e002a7768c0e2dCAS |

Carnevale, E. M., Maclellan, L. J., Coutinho da Silva, M. A., Checura, C. M., Scoggin, C. F., and Squires, E. L. (2001a). Equine sperm–oocyte interaction: results after intraoviductal and intrauterine inseminations of recipients for oocyte transfer. Anim. Reprod. Sci. 68, 305–314.
Equine sperm–oocyte interaction: results after intraoviductal and intrauterine inseminations of recipients for oocyte transfer.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3MnpslKmsw%3D%3D&md5=22f85b86a044ff3b14bf66e16641034fCAS |

Carnevale, E. M., Squires, E. L., Maclellan, L. J., Alvarenga, M. A., and Scott, T. J. (2001b). Use of oocyte transfer in a commercial breeding program for mares with reproductive abnormalities. J. Am. Vet. Med. Assoc. 218, 87–91.
Use of oocyte transfer in a commercial breeding program for mares with reproductive abnormalities.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3M7hs1KmtA%3D%3D&md5=394e44bafca7dcf6bed58ef49a0595eaCAS |

Carnevale, E. M., Maclellan, L. J., Coutinho da Silva, M. A., and Squires, E. L. (2003). Pregnancies attained after collection and transfer of oocytes from ovaries of five euthanatized mares. J. Am. Vet. Med. Assoc. 222, 60–62.
Pregnancies attained after collection and transfer of oocytes from ovaries of five euthanatized mares.Crossref | GoogleScholarGoogle Scholar |

Carnevale, E. M., Coutinho da Silva, M. A., Maclellan, L. J., Seidel, G. E., and Squires, E. L. (2004a). Use of parentage testing to determine optimum insemination time and culture media for oocyte transfer in mares. Reproduction 128, 623–628.
Use of parentage testing to determine optimum insemination time and culture media for oocyte transfer in mares.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXhtVSis7nJ&md5=a605b4e8f090d943851910160f792a46CAS |

Carnevale, E. M., Coutinho da Silva, M. A., Preis, K. A., Stokes, J. E., and Squires, E. L. (2004b). Establishment of pregnancies from oocytes collected from the ovaries of euthanized mares. Proc. Am. Ass. Equine Practnrs. 50, 531–533.

Carnevale, E. M., Coutinho da Silva, M. A., Panzani, D., Stokes, J. E., and Squires, E. L. (2005). Factors affecting the success of oocyte transfer in a clinical program for subfertile mares. Theriogenology 64, 519–527.
Factors affecting the success of oocyte transfer in a clinical program for subfertile mares.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2MzmslKntQ%3D%3D&md5=7f56198fd6814afd354be23e3b18ee12CAS |

Choi, Y. H., Okada, Y., Hochi, S., Braun, J., Sato, K., and Oguri, N. (1994). In vitro fertilization rate of horse oocytes with partially removed zonae. Theriogenology 42, 795–802.
In vitro fertilization rate of horse oocytes with partially removed zonae.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD28zgtVensA%3D%3D&md5=a7a7ddd23142d98e2365a7353f2a5f4dCAS |

Choi, Y. H., Love, C. C., Love, L. B., Varner, D. D., Brinsko, S., and Hinrichs, K. (2002). Developmental competence in vivo and in vitro of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection with fresh or frozen–thawed sperm. Reproduction 123, 455–465.
Developmental competence in vivo and in vitro of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection with fresh or frozen–thawed sperm.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xit1Cls7o%3D&md5=e66e57a1b3096ea4f0c4fa3d11bb6b12CAS |

Choi, Y. H., Love, C. C., Varner, D. D., Love, L. B., and Hinrichs, K. (2003). Effects of gas conditions, time of medium change, and ratio of medium to embryo on in vitro development of horse oocytes fertilized by intracytoplasmic sperm injection. Theriogenology 59, 1219–1229.
Effects of gas conditions, time of medium change, and ratio of medium to embryo on in vitro development of horse oocytes fertilized by intracytoplasmic sperm injection.Crossref | GoogleScholarGoogle Scholar |

Choi, Y. H., Love, L. B., Varner, D. D., and Hinrichs, K. (2004a). Factors affecting developmental competence of equine oocytes after intracytoplasmic sperm injection. Reproduction 127, 187–194.
Factors affecting developmental competence of equine oocytes after intracytoplasmic sperm injection.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXitVWrt7s%3D&md5=3548c70f9d3e6cdea9690f86d3d8947aCAS |

Choi, Y. H., Roasa, L. M., Love, C. C., Varner, D. D., Brinsko, S. P., and Hinrichs, K. (2004b). Blastocyst formation rates in vivo and in vitro of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection. Biol. Reprod. 70, 1231–1238.
Blastocyst formation rates in vivo and in vitro of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXjsFelt7w%3D&md5=114cad44d6f94f6dab6e17e37a6c1da6CAS |

Choi, Y. H., Love, L. B., Varner, D. D., and Hinrichs, K. (2006). Holding immature equine oocytes in the absence of meiotic inhibitors: Effect on germinal vesicle chromatin and blastocyst development after intracytoplasmic sperm injection. Theriogenology 66, 955–963.
Holding immature equine oocytes in the absence of meiotic inhibitors: Effect on germinal vesicle chromatin and blastocyst development after intracytoplasmic sperm injection.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xot1Wrur8%3D&md5=b22f30c751914640aa442658966af7b6CAS |

Choi, Y. H., Love, L. B., Varner, D. D., and Hinrichs, K. (2007). Effect of holding technique and culture drop size in individual or group culture on blastocyst development after ICSI of equine oocytes with low meiotic competence. Anim. Reprod. Sci. 102, 38–47.
Effect of holding technique and culture drop size in individual or group culture on blastocyst development after ICSI of equine oocytes with low meiotic competence.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2snitFKkuw%3D%3D&md5=9003028aab5b712425f5b598576884cdCAS |

Choi, Y. H., Hartman, D. L., Fissore, R. A., Bedford-Guaus, S. J., and Hinrichs, K. (2009). Effect of sperm extract injection volume, injection of PLCζ cRNA, and tissue cell line on efficiency of equine nuclear transfer. Cloning Stem Cells 11, 301–308.
Effect of sperm extract injection volume, injection of PLCζ cRNA, and tissue cell line on efficiency of equine nuclear transfer.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXnt1Cis74%3D&md5=45f6f756bdaba7590737f43a0f438ab2CAS |

Choi, Y. H., Gustafson-Seabury, A., Velez, I. C., Hartman, D. L., Bliss, S., Riera, F. L., Roldan, J. E., Chowdhary, B., and Hinrichs, K. (2010). Viability of equine embryos after puncture of the capsule and biopsy for preimplantation genetic diagnosis. Reproduction 140, 893–902.
Viability of equine embryos after puncture of the capsule and biopsy for preimplantation genetic diagnosis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXisFKqtbs%3D&md5=f202656842a342bd12352a0d231a9d77CAS |

Choi, Y. H., Varner, D. D., Love, C. C., Hartman, D. L., and Hinrichs, K. (2011a). Production of live foals via intracytoplasmic injection of lyophilized sperm and sperm extract in the horse. Reproduction 142, 529–538.
Production of live foals via intracytoplasmic injection of lyophilized sperm and sperm extract in the horse.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhtlyitb%2FJ&md5=3db814292f963f33fea92aa3f00e7151CAS |

Choi, Y. H., Velez, I. C., Riera, F. L., Roldan, J. E., Hartman, D. L., Bliss, S. B., Blanchard, T. L., Hayden, S. S., and Hinrichs, K. (2011b). Successful cryopreservation of expanded equine blastocysts. Theriogenology 76, 143–152.
Successful cryopreservation of expanded equine blastocysts.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXntFKitbg%3D&md5=91cc562735a146efe37464d28c5b6a40CAS |

Choi, Y. H., Penedo, C., Velez, I. C., and Hinrichs, K. (2012). Accuracy of preimplantation genetic diagnosis using cells biopsied from equine blastocysts. Reprod. Fertil. Dev. 24, 163–164.
Accuracy of preimplantation genetic diagnosis using cells biopsied from equine blastocysts.Crossref | GoogleScholarGoogle Scholar |

Cobo, A., Meseguer, M., Remohi, J., and Pellicer, A. (2010). Use of cryo-banked oocytes in an ovum donation programme: a prospective, randomized, controlled, clinical trial. Hum. Reprod. 25, 2239–2246.
Use of cryo-banked oocytes in an ovum donation programme: a prospective, randomized, controlled, clinical trial.Crossref | GoogleScholarGoogle Scholar |

Cochran, R., Meintjes, M., Reggio, B., Hylan, D., Carter, J., Pinto, C., Paccamonti, D., and Godke, R. A. (1998). Live foals produced from sperm-injected oocytes derived from pregnant mares. J. Equine Vet. Sci. 18, 736–740.
Live foals produced from sperm-injected oocytes derived from pregnant mares.Crossref | GoogleScholarGoogle Scholar |

Colleoni, S., Barbacini, S., Necci, D., Duchi, R., Lazzari, G., and Galli, C. (2007). Application of ovum pick-up, intracytoplasmic sperm injection and embryo culture in equine practice. Proc. Am. Ass. Equine Practnrs. 53, 554–559.

Colleoni, S., Spincaci, M., Duchi, R., Merlo, B., Tamanini, C., Lazzari, G., Mari, G., and Galli, C. (2009). ICSI of equine oocytes with sex-sorted frozen-thawed semen results in low cleavage rate but normal embryo development and pregnancies Reprod. Fertil. Dev. 21, 228–229.
ICSI of equine oocytes with sex-sorted frozen-thawed semen results in low cleavage rate but normal embryo development and pregnanciesCrossref | GoogleScholarGoogle Scholar |

Cook, N. L., Squires, E. L., and Jasko, D. J. (1993). Repeated transvaginal follicular aspiration in cyclic mares Theriogenology 39, 204.
Repeated transvaginal follicular aspiration in cyclic maresCrossref | GoogleScholarGoogle Scholar |

Coutinho da Silva, M. A., Carnevale, E. M., Maclellan, L. J., Seidel, G. E., and Squires, E. L. (2002). Effect of time of oocyte collection and site of insemination on oocyte transfer in mares. J. Anim. Sci. 80, 1275–1279.
| 1:CAS:528:DC%2BD38XmvVektr4%3D&md5=17b4f0c690a82b327434488e595b0cedCAS |

Coutinho da Silva, M. A., Carnevale, E. M., Maclellan, L. J., Preis, K. A., Seidel, G. E., and Squires, E. L. (2004). Oocyte transfer in mares with intrauterine or intraoviductal insemination using fresh, cooled, and frozen stallion semen. Theriogenology 61, 705–713.
Oocyte transfer in mares with intrauterine or intraoviductal insemination using fresh, cooled, and frozen stallion semen.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2c%2FgtlKnsg%3D%3D&md5=7200c77c2eba2ee5b2565a9c7ae6b0bfCAS |

Davies Morel, M. C., and Newcombe, J. R. (2008). The efficacy of different hCG dose rates and the effect of hCG treatment on ovarian activity: ovulation, multiple ovulation, pregnancy, multiple pregnancy, synchrony of multiple ovulation; in the mare. Anim. Reprod. Sci. 109, 189–199.
The efficacy of different hCG dose rates and the effect of hCG treatment on ovarian activity: ovulation, multiple ovulation, pregnancy, multiple pregnancy, synchrony of multiple ovulation; in the mare.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXht12gu7zN&md5=089e5b7bf257b3ffbd07a4717165950cCAS |

de Leon, P. M. M., Campos, V. F., Corcini, C. D., Santos, E. C. S., Rambo, G., Lucia, T., Deschamps, J. C., and Collares, T. (2012). Cryopreservation of immature equine oocytes, comparing a solid surface vitrification process with open pulled straws and the use of a synthetic ice blocker. Theriogenology 77, 21–27.
Cryopreservation of immature equine oocytes, comparing a solid surface vitrification process with open pulled straws and the use of a synthetic ice blocker.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhsF2rt7vP&md5=e94b4149293cadcc274b407b769b759fCAS |

Deleuze, S., Goudet, G., Caillaud, M., Lahuec, C., and Duchamp, G. (2009). Efficiency of embryonic development after intrafollicular and intraoviductal transfer of in vitro and in vivo matured horse oocytes. Theriogenology 72, 203–209.
Efficiency of embryonic development after intrafollicular and intraoviductal transfer of in vitro and in vivo matured horse oocytes.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD1MvivFGmtA%3D%3D&md5=db6a653e7aca13e821915b12b9b7e3ecCAS |

Deleuze, S., Dubois, C. S., Caillaud, M., Bruneau, B., Goudet, G., and Duchamp, G. (2010). Influence of cysteamine on in vitro maturation, in vitro and in vivo fertilization of equine oocytes. Reprod. Domest. Anim. 45, 1–7.
Influence of cysteamine on in vitro maturation, in vitro and in vivo fertilization of equine oocytes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXislagur8%3D&md5=93a289a7f46adb2d5b08970a4a44dac3CAS |

Dell’Aquila, M. E., Fusco, S., Lacalandra, G. M., and Maritato, F. (1996). In vitro maturation and fertilization of equine oocytes recovered during the breeding season. Theriogenology 45, 547–560.
In vitro maturation and fertilization of equine oocytes recovered during the breeding season.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD28zgtVGktw%3D%3D&md5=3fdcb0f24c1264f8784489026a8753cdCAS |

Dell’Aquila, M. E., Masterson, M., Maritato, F., and Hinrichs, K. (2001). Influence of oocyte collection technique on initial chromatin configuration, meiotic competence, and male pronucleus formation after intracytoplasmic sperm injection (ICSI) of equine oocytes. Mol. Reprod. Dev. 60, 79–88.
Influence of oocyte collection technique on initial chromatin configuration, meiotic competence, and male pronucleus formation after intracytoplasmic sperm injection (ICSI) of equine oocytes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXlvFWis7w%3D&md5=0f58d684e68abc8545ef17f6d72ec481CAS |

Duchamp, G., Bour, B., Combarnous, Y., and Palmer, E. (1987). Alternative solutions to hCG induction of ovulation in the mare. J. Reprod. Fertil. Suppl. 35, 221–228.
| 1:CAS:528:DyaL1cXnt1U%3D&md5=ab124508f5f6f45ec379bb148a34d1e9CAS |

Duchamp, G., Bézard, J., and Palmer, E. (1995). Oocyte yield and the consequences of puncture of all follicles larger than 8 millimetres in mares. Biol. Reprod. Monogr. 1, 233–241.

Eldridge-Panuska, W. D., Caracciolo di Brienza, V., Seidel, G. E., Squires, E. L., and Carnevale, E. M. (2005). Establishment of pregnancies after serial dilution or direct transfer by vitrified equine embryos. Theriogenology 63, 1308–1319.
Establishment of pregnancies after serial dilution or direct transfer by vitrified equine embryos.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2M%2Fps1Witw%3D%3D&md5=6e3cc25f29f7536f4e306b9463ea041eCAS |

Enders, A. C., and Liu, I. K. M. (1991). Lodgement of the equine blastocyst in the uterus from fixation through endometrial cup formation. J. Reprod. Fertil. Suppl. 44, 427–438.
| 1:STN:280:DyaK387nslamsg%3D%3D&md5=2795f5148e32e7127aec9e2e79ba7771CAS |

Flood, P. F., Betteridge, K. J., and Diocee, M. S. (1982). Transmission electron microscopy of horse embryos 3–16 days after ovulation. J. Reprod. Fertil. Suppl. 32, 319–327.
| 1:STN:280:DyaL3s7mtl2ltw%3D%3D&md5=a21529bf46e4382f4f30ad27c233ebedCAS |

Freeman, D. A., Weber, J. A., Geary, R. T., and Woods, G. L. (1991). Time of embryo transport through the mare oviduct. Theriogenology 36, 823–830.
Time of embryo transport through the mare oviduct.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD283pvFyitg%3D%3D&md5=8a48fe302aab3ccf0b45e088051836ddCAS |

Galli, C., Lagutina, I., Crotti, G., Colleoni, S., Turini, P., Ponderato, N., Duchi, R., and Lazzari, G. (2003). A cloned horse born to its dam twin. Nature 424, 635.
A cloned horse born to its dam twin.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXmtVektbc%3D&md5=8ccbbbe7b6655eda1eeaa73f9776ad21CAS |

Gambini, A., Jarazo, J., Olivera, R., and Salamone, D. F. (2012). Equine cloning: in vitro and in vivo development of aggregated embryos. Biol. Reprod. 87, .
Equine cloning: in vitro and in vivo development of aggregated embryos.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhsVentrjO&md5=bf813ea6f8d5828addbd295b40526c08CAS |

Ginther, O. J. 1986. Factors affecting incidence of double ovulations. In ‘Ultrasonic Imaging and Reproductive Events in the Mare’. pp. 290–292 (Equiservices: Cross Plains, WI.)

González-Fernández, L., Macías-García, B., Velez, I. C., Varner, D. D., and Hinrichs, K. (2012). Calcium-calmodulin and pH regulate protein tyrosine phosphorylation in stallion sperm. Reproduction , .
Calcium-calmodulin and pH regulate protein tyrosine phosphorylation in stallion sperm.Crossref | GoogleScholarGoogle Scholar |

Grondahl, C., Host, T., Brück, I., Viuff, D., Bézard, J., Fair, T., Greve, T., and Hyttel, P. (1995). In vitro production of equine embryos. Biol. Reprod. Monograph 1, 299–307.

Hawley, L. R., Enders, A. C., and Hinrichs, K. (1995). Comparison of equine and bovine oocyte–cumulus morphology within the ovarian follicle. Biol. Reprod. Monogr. 1, 243–252.

Hinrichs, K. (1991). The relationship of follicle atresia to follicle size, oocyte recovery rate on aspiration, and oocyte morphology in the mare. Theriogenology 36, 157–168.
The relationship of follicle atresia to follicle size, oocyte recovery rate on aspiration, and oocyte morphology in the mare.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD283pvFOmsA%3D%3D&md5=bafc2a618b9471c6dbcd477a7aad71b8CAS |

Hinrichs, K., and DiGiorgio, L. M. (1991). Embryonic development after intrafollicular transfer of horse oocytes. J. Reprod. Fertil. Suppl. 44, 369–374.
| 1:STN:280:DyaK387nslansA%3D%3D&md5=2f84df32127a1b3a2bd64fb5a3068762CAS |

Hinrichs, K., and Schmidt, A. L. (2000). Meiotic competence in horse oocytes: interactions among chromatin configuration, follicle size, cumulus morphology, and season. Biol. Reprod. 62, 1402–1408.
Meiotic competence in horse oocytes: interactions among chromatin configuration, follicle size, cumulus morphology, and season.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXisl2htbc%3D&md5=19503ff0035cfa7e1920722ec323a189CAS |

Hinrichs, K., and Williams, K. A. (1997). Relationships among oocyte–cumulus morphology, follicular atresia, initial chromatin configuration, and oocyte meiotic competence in the horse. Biol. Reprod. 57, 377–384.
Relationships among oocyte–cumulus morphology, follicular atresia, initial chromatin configuration, and oocyte meiotic competence in the horse.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXkslWgtLo%3D&md5=2a9be092d9821c56c8e51cfec90f6ce6CAS |

Hinrichs, K., Kenney, D. F., and Kenney, R. M. (1990). Aspiration of oocytes from mature and immature preovulatory follicles in the mare. Theriogenology 34, 107–112.
Aspiration of oocytes from mature and immature preovulatory follicles in the mare.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD283pvFGrsQ%3D%3D&md5=584762c70212cac7bc8cc6ddf213f917CAS |

Hinrichs, K., Matthews, G. L., Freeman, D. A., and Torello, E. M. (1998). Oocyte transfer in mares. J. Am. Vet. Med. Assoc. 212, 982–986.
| 1:STN:280:DyaK1c3gtFOntw%3D%3D&md5=1eb4d8bc616dafc0fef76cc8d62d6aebCAS |

Hinrichs, K., Provost, P. J., and Torello, E. M. (1999). Birth of a foal after oocyte transfer to a nonovulating, hormone-treated mare. Theriogenology 51, 1251–1258.
Birth of a foal after oocyte transfer to a nonovulating, hormone-treated mare.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3c7ptFCgsQ%3D%3D&md5=e6318bf0503d013a780c5a91970a92bdCAS |

Hinrichs, K., Betschart, R. W., McCue, P. M., and Squires, E. L. (2000a). Effect of timing of follicle aspiration on pregnancy rate after oocyte transfer in mares. J. Reprod. Fertil. Suppl. 56, 493–498.

Hinrichs, K., Provost, P. J., and Torello, E. M. (2000b). Treatments resulting in pregnancy in nonovulating, hormone-treated oocyte recipient mares. Theriogenology 54, 1285–1293.
Treatments resulting in pregnancy in nonovulating, hormone-treated oocyte recipient mares.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3M7ptFansw%3D%3D&md5=6ea77240ac1c5ee258f1b0931201a0aeCAS |

Hinrichs, K., Love, C. C., Brinsko, S. P., Choi, Y. H., and Varner, D. D. (2002). In vitro fertilization of in vitro-matured equine oocytes: Effect of maturation medium, duration of maturation, and sperm calcium ionophore treatment, and comparison with rates of fertilization in vivo after oviductal transfer. Biol. Reprod. 67, 256–262.
In vitro fertilization of in vitro-matured equine oocytes: Effect of maturation medium, duration of maturation, and sperm calcium ionophore treatment, and comparison with rates of fertilization in vivo after oviductal transfer.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XkvV2itbs%3D&md5=14ba8befe01097a8574a762222b80c78CAS |

Hinrichs, K., Choi, Y. H., Love, L. B., Varner, D. D., Love, C. C., and Walckenaer, B. E. (2005). Chromatin configuration within the germinal vesicle of horse oocytes: changes post mortem and relationship to meiotic and developmental competence. Biol. Reprod. 72, 1142–1150.
Chromatin configuration within the germinal vesicle of horse oocytes: changes post mortem and relationship to meiotic and developmental competence.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXjslSntrw%3D&md5=2d1eaa9518251b3e9741cda35334af4bCAS |

Hinrichs, K., Choi, Y. H., Love, C. C., Chung, Y. G., and Varner, D. D. (2006). Production of horse foals via direct injection of roscovitine-treated donor cells and activation by injection of sperm extract. Reproduction 131, 1063–1072.
Production of horse foals via direct injection of roscovitine-treated donor cells and activation by injection of sperm extract.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xpt1ehurw%3D&md5=bc24a1a071632f3f78538af91619fbbfCAS |

Hinrichs, K., Choi, Y. H., Varner, D. D., and Hartman, D. L. (2007a). Production of cloned horse foals using roscovitine-treated donor cells and activation with sperm extract and/or ionomycin. Reproduction 134, 319–325.
Production of cloned horse foals using roscovitine-treated donor cells and activation with sperm extract and/or ionomycin.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhtVKls77O&md5=d8681ad609f55568a015d2b647f32e1dCAS |

Hinrichs, K., Choi, Y. H., Walckenaer, B. E., Varner, D. D., and Hartman, D. L. (2007b). In vitro-produced equine embryos: production of foals after transfer, assessment by differential staining, and effect of medium calcium concentrations during culture. Theriogenology 68, 521–529.
In vitro-produced equine embryos: production of foals after transfer, assessment by differential staining, and effect of medium calcium concentrations during culture.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXotlWqurc%3D&md5=54221ab3251202dc8fe32cf65e42e6aaCAS |

Hinrichs, K., Choi, Y. H., Norris, J. D., Love, L. B., Bedford-Guaus, S. J., Hartman, D. L., and Velez, I. C. (2012). Evaluation of foal production following intracytoplasmic sperm injection and blastocyst culture of oocytes from ovaries collected immediately before euthanasia or after death of mares under field conditions. J. Am. Vet. Med. Assoc. 241, .

Hiraoka, K., Hiraoka, K., Kinutani, M., and Kinutani, K. (2004). Blastocoele collapse by micropipetting prior to vitrification gives excellent survival and pregnancy outcomes for human day 5 and 6 expanded blastocysts. Hum. Reprod. 19, 2884–2888.
Blastocoele collapse by micropipetting prior to vitrification gives excellent survival and pregnancy outcomes for human day 5 and 6 expanded blastocysts.Crossref | GoogleScholarGoogle Scholar |

Huhtinen, M., Peippo, J., and Bredbacka, P. (1997). Successful transfer of biopsied equine embryos. Theriogenology 48, 361–367.
Successful transfer of biopsied equine embryos.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD28zgtVyrtw%3D%3D&md5=86756d809e5eb65d935999a59ad9e12aCAS |

Jacobson, C. C., Choi, Y. H., Hayden, S. S., and Hinrichs, K. (2010). Recovery of mare oocytes on a fixed biweekly schedule, and resulting blastocyst formation after intracytoplasmic sperm injection. Theriogenology 73, 1116–1126.
Recovery of mare oocytes on a fixed biweekly schedule, and resulting blastocyst formation after intracytoplasmic sperm injection.Crossref | GoogleScholarGoogle Scholar |

Johnson, A. K., Clark-Price, S., Choi, Y. H., Hartman, D. L., and Hinrichs, K. (2010). Physical and clinicopathologic findings in foals produced by somatic cell nuclear transfer: 14 cases (2005–2008). J. Am. Vet. Med. Assoc. 236, 983–990.
Physical and clinicopathologic findings in foals produced by somatic cell nuclear transfer: 14 cases (2005–2008).Crossref | GoogleScholarGoogle Scholar |

Kanitz, W., Becker, F., Alm, H., and Torner, H. (1995). Ultrasound-guided follicular aspiration in mares. Biol. Reprod. Monograph 1, 225–231.

Köllmann, M., Rötting, A., Heberling, A., and Sieme, H. (2011). Laparoscopic techniques for investigating the equine oviduct. Equine Vet. J. 43, 106–111.
Laparoscopic techniques for investigating the equine oviduct.Crossref | GoogleScholarGoogle Scholar |

Kuwayama, M., Vajta, G., Kato, O., and Leibo, S. P. (2005). Highly efficient vitrification method for cryopreservation of human oocytes. Reprod. Biomed. Online 11, 300–308.
Highly efficient vitrification method for cryopreservation of human oocytes.Crossref | GoogleScholarGoogle Scholar |

Lagutina, I., Lazzari, G., Duchi, R., Colleoni, S., Ponderato, N., Turini, P., Crotti, G., and Galli, C. (2005). Somatic cell nuclear transfer in horses: effect of oocyte morphology, embryo reconstruction method and donor cell type. Reproduction 130, 559–567.
Somatic cell nuclear transfer in horses: effect of oocyte morphology, embryo reconstruction method and donor cell type.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXhtFent7vP&md5=335ca345042c2d547aa81786378b5232CAS |

Lane, M. (2001). Mechanisms for managing cellular and homeostatic stress in vitro. Theriogenology 55, 225–236.
Mechanisms for managing cellular and homeostatic stress in vitro.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3M7nslarug%3D%3D&md5=5d2c5fffb341c65364850bf40b223cabCAS |

Lazzari, G., Crotti, G., Turini, P., Duchi, R., Mari, G., Zavaglia, G., Barbacini, S., and Galli, C. (2002). Equine embryos at the compacted morula and blastocyst stage can be obtained by intracytoplasmic sperm injection (ICSI) of in vitro matured oocytes with frozen–thawed spermatozoa from semen of different fertilities. Theriogenology 58, 709–712.
Equine embryos at the compacted morula and blastocyst stage can be obtained by intracytoplasmic sperm injection (ICSI) of in vitro matured oocytes with frozen–thawed spermatozoa from semen of different fertilities.Crossref | GoogleScholarGoogle Scholar |

Legrand, E., Bencharif, D., Barrier-Battut, I., Delajarraud, H., Corniere, P., Fieni, F., Tainturier, D., and Bruyas, J. F. (2002). Comparison of pregnancy rates for Days 7–8 equine embryos frozen in glycerol with or without previous enzymatic treatment of their capsule. Theriogenology 58, 721–723.
Comparison of pregnancy rates for Days 7–8 equine embryos frozen in glycerol with or without previous enzymatic treatment of their capsule.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XkvFymt70%3D&md5=2c50b2ee3233bf93526120ecbbec07f3CAS |

Li, L. Y., Meintjes, M., Graff, K. J., Paul, J. B., Denniston, R. S., and Godke, R. A. (1995). In vitro fertilization and development of in vitro-matured oocytes aspirated from pregnant mares. Biol. Reprod. Monogr. 1, 309–317.

Li, X., Morris, L. H. A., and Allen, W. R. (2001). Influence of co-culture during maturation on the developmental potential of equine oocytes fertilized by intracytoplasmic sperm injection (ICSI). Reproduction 121, 925–932.
Influence of co-culture during maturation on the developmental potential of equine oocytes fertilized by intracytoplasmic sperm injection (ICSI).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXkslWntrk%3D&md5=f3bae65ae64403d5372f776e7199d9d5CAS |

Lin, L., Du, Y., Kragh, P. M., Li, J., Bolund, L., Yang, H., Zhang, X., Kuwayama, M., and Vajta, G. (2008). Induced blastocoel collapse improves survival rates of porcine blastocysts after vitrification. Reprod. Fertil. Dev. 20, 121.
Induced blastocoel collapse improves survival rates of porcine blastocysts after vitrification.Crossref | GoogleScholarGoogle Scholar |

Maclellan, L. J., Carnevale, E. M., Coutinho da Silva, M. A., McCue, P. M., Seidel, G. E., and Squires, E. L. (2002a). Cryopreservation of small and large equine embryos pre-treated with cytochalasin-B and/or trypsin. Theriogenology 58, 717–720.
Cryopreservation of small and large equine embryos pre-treated with cytochalasin-B and/or trypsin.Crossref | GoogleScholarGoogle Scholar |

Maclellan, L. J., Carnevale, E. M., Coutinho da Silva, M. A., Scoggin, C. F., Bruemmer, J. E., and Squires, E. L. (2002b). Pregnancies from vitrified equine oocytes collected from super-stimulated and non-stimulated mares. Theriogenology 58, 911–919.
Pregnancies from vitrified equine oocytes collected from super-stimulated and non-stimulated mares.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xls1WkurY%3D&md5=b629dcf5d03597bbe82b0ba204200e6bCAS |

Maclellan, L. J., Stokes, J. E., Preis, K. A., McCue, P. M., and Carnevale, E. M. (2010). Vitrification, warming, ICSI and transfer of equine oocytes matured in vivo. Anim. Reprod. Sci. 121S, S260–S261.

Mari, G., Merlo, B., Iacono, E., and Belluzzi, S. (2005). Fertility in the mare after repeated transvaginal ultrasound-guided aspirations. Anim. Reprod. Sci. 88, 299–308.
Fertility in the mare after repeated transvaginal ultrasound-guided aspirations.Crossref | GoogleScholarGoogle Scholar |

McCue, P. M., LeBlanc, M. M., and Squires, E. L. (2007). eFSH in clinical equine practice. Theriogenology 68, 429–433.
eFSH in clinical equine practice.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXnsFKls7w%3D&md5=18aa47abe48cc17da5a415d0862ec6d4CAS |

McKinnon, A. O., Carnevale, E. M., Squires, E. L., Carney, N. J., and Seidel, G. E. (1989). Bisection of equine embryos. Equine Vet. J. Suppl. 8, 129–133.

McKinnon, A. O., Lacham-Kaplan, O., and Trounson, A. O. (2000). Pregnancies produced from fertile and infertile stallions by intracytoplasmic sperm injection (ICSI) of single frozen–thawed spermatozoa into in vivo matured mare oocytes. J. Reprod. Fertil. Suppl. 56, 513–517.

McPartlin, L. A., Littell, J., Mark, E., Nelson, J. L., Travis, A. J., and Bedford-Guaus, S. J. (2008). A defined medium supports changes consistent with capacitation in stallion sperm, as evidenced by increases in protein tyrosine phosphorylation and high rates of acrosomal exocytosis. Theriogenology 69, 639–650.
A defined medium supports changes consistent with capacitation in stallion sperm, as evidenced by increases in protein tyrosine phosphorylation and high rates of acrosomal exocytosis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXislKksbY%3D&md5=fbe48f450a595939d4aa2a0d1e1a93bfCAS |

McPartlin, L. A., Suarez, S. S., Czaya, C. A., Hinrichs, K., and Bedford-Guaus, S. J. (2009). Hyperactivation of stallion sperm is required for successful in vitro fertilization of equine oocytes. Biol. Reprod. 81, 199–206.
Hyperactivation of stallion sperm is required for successful in vitro fertilization of equine oocytes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXnslaqs7w%3D&md5=0b96c378dd59982f9fb1473a2418720cCAS |

Meyers-Brown, G., Bidstrup, L. A., Famula, T. R., Colgin, M., and Roser, J. F. (2011). Treatment with recombinant equine follicle stimulating hormone (reFSH) followed by recombinant equine luteinizing hormone (reLH) increases embryo recovery in superovulated mares. Anim. Reprod. Sci. 128, 52–59.
Treatment with recombinant equine follicle stimulating hormone (reFSH) followed by recombinant equine luteinizing hormone (reLH) increases embryo recovery in superovulated mares.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhsVamsr%2FK&md5=3b2e7cd8098e5b041c051e517c446bfdCAS |

Mukaida, T., Oka, C., Goto, T., and Takahashi, K. (2006). Artificial shrinkage of blastocoeles using either a micro-needle or a laser pulse prior to the cooling steps of vitrification improves survival rate and pregnancy outcome of vitrified human blastocysts. Hum. Reprod. 21, 3246–3252.
Artificial shrinkage of blastocoeles using either a micro-needle or a laser pulse prior to the cooling steps of vitrification improves survival rate and pregnancy outcome of vitrified human blastocysts.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtlChtb7P&md5=088d2a78fb66997b3ba5598a45c93516CAS |

Oriol, J. G., Betteridge, K. J., Clarke, A. J., and Sharom, F. J. (1993a). Mucin-like glycoproteins in the equine embryonic capsule. Mol. Reprod. Dev. 34, 255–265.
Mucin-like glycoproteins in the equine embryonic capsule.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXktVGlsr8%3D&md5=e762c5d12471f1b05f2d9d9a3313a2a4CAS |

Oriol, J. G., Sharom, F. J., and Betteridge, K. J. (1993b). Developmentally regulated changes in the glycoproteins of the equine embryonic capsule. J. Reprod. Fertil. 99, 653–664.
Developmentally regulated changes in the glycoproteins of the equine embryonic capsule.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXitFentbc%3D&md5=523eb89769e1f5112961a7ff4c29453eCAS |

Palmer, E., Bézard, J., Magistrini, M., and Duchamp, G. (1991). In vitro fertilisation in the horse: a retrospective study. J. Reprod. Fertil. Suppl. 44, 375–384.
| 1:STN:280:DyaK387nslantg%3D%3D&md5=5d0a57b4eb03dd1a048cdf81da58ed29CAS |

Pascoe, D. R., Pascoe, R. R., Hughes, J. P., Stabenfeldt, G. H., and Kindahl, H. (1987). Management of twin conceptuses by manual embryonic reduction: comparison of two techniques and three hormone treatments. Am. J. Vet. Res. 48, 1594–1599.
| 1:CAS:528:DyaL2sXmt12nu7s%3D&md5=ac3e4457cd568b8ce9090d742cd4ae5bCAS |

Preis, K. A., Carnevale, E. M., Coutinho da Silva, M. A., Caracciolo di Brienza, V., Gomes, G. M., Maclellan, L. J., and Squires, E. L. (2004). In vitro maturation and transfer of equine oocytes after transport of ovaries at 12 or 22 degrees C. Theriogenology 61, 1215–1223.
In vitro maturation and transfer of equine oocytes after transport of ovaries at 12 or 22 degrees C.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2c7ksVOjsg%3D%3D&md5=e5c5ba8554bf5ffcb2aa4edf76cc0cedCAS |

Ribeiro, B. I., Love, L. B., Choi, Y. H., and Hinrichs, K. (2008). Transport of equine ovaries for assisted reproduction. Anim. Reprod. Sci. 108, 171–179.
Transport of equine ovaries for assisted reproduction.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD1crislyqtQ%3D%3D&md5=db1de68096d1386070149e903a19a969CAS |

Riera, F. L., Roldan, J. E., and Hinrichs, K. (2006). Patterns of embryo recovery in mares with unilateral and bilateral double ovulations. Anim. Reprod. Sci. 94, 398–399.
Patterns of embryo recovery in mares with unilateral and bilateral double ovulations.Crossref | GoogleScholarGoogle Scholar |

Rosati, I., Maclellan, L. J., Ariu, F., Bogliolo, L., Zedda, M. T., Pau, S., Carnevale, E. M., and Ledda, S. (2012). Vitrification of GV and IVM horse oocytes with two different equilibration methods. Reprod. Domest. Anim. 47, 436–437.

Scott, T. J., Carnevale, E. M., Maclellan, L. J., Scoggin, C. F., and Squires, E. L. (2001). Embryo development rates after transfer of oocytes matured in vivo, in vitro, or within oviducts of mares. Theriogenology 55, 705–715.
Embryo development rates after transfer of oocytes matured in vivo, in vitro, or within oviducts of mares.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3MzgtFOrtw%3D%3D&md5=0584506ed4447a615392d0688aea9facCAS |

Seidel, G. E., Cullingford, E. L., Stokes, J. E., Carnevale, E. M., and McCue, P. M. (2010). Pregnancy rates following transfer of biopsied and/or vitrified equine embryos: evaluation of two biopsy techniques. Anim. Reprod. Sci. 121S, 297–298.

Sieme, H., Schäfer, T., Stout, T. A. E., Klug, E., and Waberski, D. (2003). The effects of different insemination regimes on fertility in mares. Theriogenology 60, 1153–1164.
The effects of different insemination regimes on fertility in mares.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3szpvFCmuw%3D%3D&md5=1231981363b94c59c402a4526c6fa3ceCAS |

Skidmore, J., Boyle, M. S., Cran, D., and Allen, W. R. (1989). Micromanipulation of equine embryos to produce monozygotic twins. Equine Vet. J. Suppl. 8, 126–128.

Slade, N. P., Takeda, T., Squires, E. L., Elsden, R. P., and Seidel, G. E. (1985). A new procedure for the cryopreservation of equine embryos. Theriogenology 24, 45–58.
A new procedure for the cryopreservation of equine embryos.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD283pvVyhtw%3D%3D&md5=62b8baf27fa62f7bf1f8728b4986070aCAS |

Squires, E. L., and McCue, P. M. (2007). Superovulation in mares. Anim. Reprod. Sci. 99, 1–8.
Superovulation in mares.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXit1Gmsrg%3D&md5=ab151a7f31d38da5fcbd479e47e85d0aCAS |

Squires, E. L., McClain, M. G., Ginther, O. J., and McKinnon, A. O. (1987). Spontaneous multiple ovulation in the mare and its effect on the incidence of twin embryo collections. Theriogenology 28, 609–613.
Spontaneous multiple ovulation in the mare and its effect on the incidence of twin embryo collections.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD283pvFWjuw%3D%3D&md5=37627fd2ea51d47c84d10937304cec05CAS |

Stout, T. A., Meadows, S., and Allen, W. R. (2005). Stage-specific formation of the equine blastocyst capsule is instrumental to hatching and to embryonic survival in vivo. Anim. Reprod. Sci. 87, 269–281.
Stage-specific formation of the equine blastocyst capsule is instrumental to hatching and to embryonic survival in vivo.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2M3mvVWitQ%3D%3D&md5=7540f61d7199d17a78753122390beba7CAS |

Stroud, B. (2010). The year 2009 worldwide statistics of embryo transfer in domestic farm animals. Embryo Transfer Newsl. 28, 11–21.

Tharasanit, T., Colenbrander, B., and Stout, T. A. (2006). Effect of maturation stage at cryopreservation on post-thaw cytoskeleton quality and fertilizability of equine oocytes. Mol. Reprod. Dev. 73, 627–637.
Effect of maturation stage at cryopreservation on post-thaw cytoskeleton quality and fertilizability of equine oocytes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xjt1KitLk%3D&md5=a0b894ce3085af8a64dd6b80a01949efCAS |

Tharasanit, T., Colleoni, S., Galli, C., Colenbrander, B., and Stout, T. A. (2009). Protective effects of the cumulus–corona radiata complex during vitrification of horse oocytes. Reproduction 137, 391–401.
Protective effects of the cumulus–corona radiata complex during vitrification of horse oocytes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXovV2ksbo%3D&md5=b2b1c657d3fe2e4621eb9029aaa96558CAS |

Troedsson, M. H. T., Paprocki, A. M., Koppang, R. W., Syverson, C. M., Griffin, P., Klein, C., and Dobrinski, J. R. (2010). Transfer success of biopsied and vitrified equine embryos. Anim. Reprod. Sci. 121, S295–S296.
Transfer success of biopsied and vitrified equine embryos.Crossref | GoogleScholarGoogle Scholar |

Tryon, R. C., Penedo, M. C. T., McCue, M. E., Valberg, S. J., Mickelson, J. R., Famula, T. R., Wagner, M. L., Jackson, M., Hamilton, M. J., Nooteboom, S., and Bannasch, D. L. (2009). Evaluation of allele frequencies of inherited disease genes in subgroups of American Quarter Horses. J. Am. Vet. Med. Assoc. 234, 120–125.
Evaluation of allele frequencies of inherited disease genes in subgroups of American Quarter Horses.Crossref | GoogleScholarGoogle Scholar |

Vogelsang, M. M., Kreider, J. L., Bowen, M. J., Potter, G. D., Forrest, D. W., and Kraemer, D. C. (1988). Methods for collecting follicular oocytes from mares. Theriogenology 29, 1007–1018.
Methods for collecting follicular oocytes from mares.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD283pvFWrug%3D%3D&md5=b37a9c342308cd5783babf5d29d4d313CAS |

Wells, D. N. (2005). Animal cloning: problems and prospects. Rev. Sci. Tech. 24, 251–264.
| 1:STN:280:DC%2BD2MvksVajtg%3D%3D&md5=5358ef24cd48b9f59003dd4276301fb4CAS |

Woods, G. L., White, K. L., Vanderwall, D. K., Li, G. P., Aston, K. I., Bunch, T. D., Meerdo, L. N., and Pate, B. J. (2003). A mule cloned from fetal cells by nuclear transfer. Science 301, 1063.
A mule cloned from fetal cells by nuclear transfer.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXms1KhurY%3D&md5=6f23b4b3c87634a9f96a55fb70379d8dCAS |

Young, C. A., Squires, E. L., Seidel, G. E., Kato, H., and McCue, P. M. (1997). Cryopreservation procedures for Day 7–8 equine embryos. Equine Vet. J. Suppl. 25, 98–102.

Zhang, J. J., Muzs, L. Z., and Boyle, M. S. (1990). In vitro fertilization of horse follicular oocytes matured in vitro. Mol. Reprod. Dev. 26, 361–365.
In vitro fertilization of horse follicular oocytes matured in vitro.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXmtVyqt7k%3D&md5=a23c1f4110539b1cc199d22b17ac8914CAS |