Current status of nonsurgical embryo transfer in swine

Maria A. Gil; Inmaculada Parrilla; Cristina Cuello; Emilio A. Martinez

doi:10.1071/RD24137

REVIEW (Open Access)

Previous Next Contents Vol 37(1)

Current status of nonsurgical embryo transfer in swine

Maria A. Gil ^A ^B , Inmaculada Parrilla ^A ^B , Cristina Cuello ^A ^B and Emilio A. Martinez

^A ^B ^*

+ Author Affiliations

- Author Affiliations

^A Department of Medicine and Animal Surgery, International Excellence Campus for Higher Education and Research ‘Campus Mare Nostrum’, University of Murcia, Murcia, Spain.

^B Institute for Biomedical Research of Murcia (IMIB-Pascual Parrilla), Murcia, Spain.

^* Correspondence to: emilio@um.es

Reproduction, Fertility and Development 37, RD24137 https://doi.org/10.1071/RD24137

© 2025 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Embryo transfer in pigs is a reproductive technology with great potential because it enables the movement of high-value genetic material, in the form of embryos, with reduced transport costs and no health risks. However, its use has been limited for decades despite significant interest, primarily due to the need for laparotomy for embryo collection from donors and deposition into recipients. Over the past 30 years, various procedures have been developed to deposit embryos nonsurgically in the body of the uterus with promising results, but none sufficiently successful. Because the uterine body is not the ideal site for embryo deposition at the morula and blastocyst stages, a new method that is capable of depositing porcine embryos deep into the uterine horn has been developed. This nonsurgical deep uterine method is a simple, effective, and well-tolerated technique in gilts and sows, achieving high fertility and prolificacy using fresh, stored, and vitrified–warmed embryos under field conditions. The present review provides a brief overview of the current status of nonsurgical deep uterine embryo transfer and addresses the varied reproductive performance observed across farms when this technology was applied in commercial programs. In addition, several future directions for its on-farm commercial application are discussed.

Keywords: assisted reproductive technology, blastocyst, embryo, embryo transfer, fertility, intrauterine device, litter size, livestock, morula, pregnancy.

References

Aigner B, Renner S, Kessler B, Klymiuk N, Kurome M, Wünsch A, Wolf E (2010) Transgenic pigs as models for translational biomedical research. Journal of Molecular Medicine 88, 653-664.
| Crossref | Google Scholar | PubMed |

Angel MA, Gil MA, Cuello C, Sanchez-Osorio J, Gomis J, Parrilla I, Vila J, Colina I, Diaz M, Reixach J, Vazquez JL, Vazquez JM, Roca J, Martinez EA (2014a) The effects of superovulation of donor sows on ovarian response and embryo development after nonsurgical deep-uterine embryo transfer. Theriogenology 81, 832-839.
| Crossref | Google Scholar | PubMed |

Angel MA, Gil MA, Cuello C, Sanchez-Osorio J, Gomis J, Parrilla I, Vila J, Colina I, Diaz M, Reixach J, Vazquez JLJ, Vazquez JM, Roca J, Martinez EA (2014b) An earlier uterine environment favors the in vivo development of fresh pig morulae and blastocysts transferred by a nonsurgical deep-uterine method. Journal of Reproduction and Development 60, 371-376.
| Crossref | Google Scholar | PubMed |

Blum-Reckow B, Holtz W (1991) Transfer of porcine embryos after 3 days of in vitro culture. Journal of Animal Science 69, 3335-3342.
| Crossref | Google Scholar | PubMed |

Cambra JM, Jauregi-Miguel A, Alvarez-Rodriguez M, Parrilla I, Gil MA, Martinez EA, Cuello C, Rodriguez-Martinez H, Martinez CA (2020) Allogeneic embryos disregulate leukemia inhibitory factor (LIF) and its receptor in the porcine endometrium during implantation. Frontiers in Veterinary Science 7, 611598.
| Crossref | Google Scholar | PubMed |

Cameron RD, Durack M, Fogarty R, Putra DK, McVeigh J (1989) Practical experience with commercial embryo transfer in pigs. Australian Veterinary Journal 66, 314-318.
| Crossref | Google Scholar | PubMed |

Clark LK, Schinckel AP, Singleton WL, Einstein ME, Teclaw RF (1989) Use of farrowing rate as a measure of fertility of boars. Journal of the American Veterinary Medical Association 194, 239-243.
| Google Scholar | PubMed |

Croy BA, Wessels J, Linton N, Tayade C (2009) Comparison of immune cell recruitment and function in endometrium during development of epitheliochorial (pig) and hemochorial (mouse and human) placentas. Placenta 30, 26-31.
| Crossref | Google Scholar |

Cuello C, Berthelot F, Martinat-Botté F, Venturi E, Guillouet P, Vázquez JM, Roca J, Martínez EA (2005) Piglets born after non-surgical deep intrauterine transfer of vitrified blastocysts in gilts. Animal Reproduction Science 85, 275-286.
| Crossref | Google Scholar | PubMed |

Cuello C, Gil MA, Almiñana C, Sanchez-Osorio J, Parrilla I, Caballero I, Vazquez JM, Roca J, Rodriguez-Martinez H, Martinez EA (2007) Vitrification of in vitro cultured porcine two-to-four cell embryos. Theriogenology 68, 258-264.
| Crossref | Google Scholar | PubMed |

Cuello C, Sanchez-Osorio J, Almiñana C, Gil MA, Perals ML, Lucas X, Roca J, Vazquez JM, Martinez EA (2008) Effect of the cryoprotectant concentration on the in vitro embryo development and cell proliferation of OPS-vitrified porcine blastocysts. Cryobiology 56, 189-194.
| Crossref | Google Scholar | PubMed |

Cuello C, Martinez CA, Nohalez A, Parrilla I, Roca J, Gil MA, Martinez EA (2016) Effective vitrification and warming of porcine embryos using a pH-stable, chemically defined medium. Scientific Reports 6, 33915.
| Crossref | Google Scholar | PubMed |

de Winter PJJ, Verdonck M, de Kruif A, Devriese LA, Haesebrouck F (1992) Endometritis and vaginal discharge in the sow. Animal Reproduction Science 28, 51-58.
| Crossref | Google Scholar |

de Winter PJJ, Verdonck M, de Kruif A, Devriese LA, Haesebrouck F (1994) Influence of the oestrous cycle on experimental intrauterine E. coli infection in the sow. Journal of Veterinary Medicine Series A 41, 640-644.
| Crossref | Google Scholar | PubMed |

Ducro-Steverink DWB, Peters CGW, Maters CC, Hazeleger W, Merks JWM (2004) Reproduction results and offspring performance after non-surgical embryo transfer in pigs. Theriogenology 62, 522-531.
| Crossref | Google Scholar | PubMed |

Dyck MK, Zhou C, Tsoi S, Grant J, Dixon WT, Foxcroft GR (2014) Reproductive technologies and the porcine embryonic transcriptome. Animal Reproduction Science 149, 11-18.
| Crossref | Google Scholar | PubMed |

Ford SP (1997) Embryonic and fetal development in different genotypes in pigs. Journal of Reproduction and Fertility. Supplements 52, 165-176.
| Google Scholar | PubMed |

Foxcroft GR, Dixon WT, Dyck MK, Novak S, Harding JCS, Almeida FCRL (2009) Prenatal programming of postnatal development in the pig. Society for Reproduction and Fertility. Supplements 66, 213-231.
| Google Scholar | PubMed |

Galvin JM, Killian DB, Stewart AN (1994) A procedure for successful nonsurgical embryo transfer in swine. Theriogenology 41, 1279-1289.
| Crossref | Google Scholar | PubMed |

Gil MA, Cuello C, Parrilla I, Vazquez JM, Roca J, Martinez EA (2010) Advances in swine in vitro embryo production technologies. Reproduction in Domestic Animals 45, 40-48.
| Crossref | Google Scholar | PubMed |

Gomis J, Cuello C, Sanchez-Osorio J, Gil MA, Parrilla I, Angel MA, Maside C, del Olmo D, Vazquez JM, Roca J, Martinez EA (2012) Non-surgical deep intrauterine transfer of superfine open pulled straw (SOPS)-vitrified porcine embryos: Evaluation of critical steps of the procedure. Theriogenology 78, 1339-1349.
| Crossref | Google Scholar | PubMed |

Gonzalez-Plaza A, Cambra JM, Parrilla I, Gil MA, Martinez EA, Martinez CA, Cuello C (2022) The open cryotop system is effective for the simultaneous vitrification of a large number of porcine embryos at different developmental stages. Frontiers in Veterinary Science 9, 936753.
| Crossref | Google Scholar | PubMed |

Gonzalez-Plaza A, Cambra JM, Garcia-Canovas M, Parrilla I, Gil MA, Martinez EA, Rodriguez-Martinez H, Martinez CA, Cuello C (2023) Cryotop vitrification of large batches of pig embryos simultaneously provides excellent postwarming survival rates and minimal interference with gene expression. Theriogenology 206, 1-10.
| Crossref | Google Scholar | PubMed |

Gonzalez-Ramiro H, Cuello C, Cambra JM, Gonzalez-Plaza A, Vazquez JM, Vazquez JL, Rodriguez-Martinez H, Gil MA, Lucas-Sanchez A, Parrilla I, Martinez EA (2021) A short-term altrenogest treatment post-weaning followed by superovulation reduces pregnancy rates and embryo production efficiency in multiparous sows. Frontiers in Veterinary Science 8, 771573.
| Crossref | Google Scholar | PubMed |

Gonzalez-Ramiro H, Parrilla I, Cambra JM, Gonzalez-Plaza A, Gil MA, Cuello C, Martinez EA, Rodriguez-Martinez H, Martinez CA (2022) Combined synchronization and superovulation treatments negatively impact embryo viability possibly by the downregulation of WNT/β-catenin and Notch signaling genes in the porcine endometrium. Journal of Animal Science 100(11), skac315.
| Crossref | Google Scholar |

Hazeleger W, Kemp B (1994) Farrowing rate and litter size after transcervical embryo transfer in sows. Reproduction in Domestic Animals 29, 481-487.
| Crossref | Google Scholar |

Hazeleger W, Bouwman EG, Noordhuizen JP, Kemp B (2000a) Effect of superovulation induction on embryonic development on day 5 and subsequent development and survival after nonsurgical embryo transfer in pigs. Theriogenology 53, 1063-1070.
| Crossref | Google Scholar | PubMed |

Hazeleger W, Noordhuizen JPTM, Kemp B (2000b) Effect of asynchronous non-surgical transfer of porcine embryos on pregnancy rate and embryonic survival. Livestock Production Science 64, 281-284.
| Crossref | Google Scholar |

Hirayama Y, Takishita R, Misawa H, Kikuchi K, Misumi K, Egawa S, Motoyama S, Hasuta Y, Nakamura Y, Hashiyada Y (2020) Non-surgical transfer of vitrified porcine embryos using a catheter designed for a proximal site of the uterus. Animal Science Journal 91, e13457.
| Crossref | Google Scholar | PubMed |

Hryhorowicz M, Lipiński D, Hryhorowicz S, Nowak-Terpiłowska A, Ryczek N, Zeyland J (2020) Application of genetically engineered pigs in biomedical research. Genes 11, 670.
| Crossref | Google Scholar |

James JE, Reeser PD, Davis DL, Straiton EC, Talbot AC, Polge C (1980) Culture and long-distance shipment of swine embryos 1. Theriogenology 14, 463-469.
| Crossref | Google Scholar |

Kraeling RR, Webel SK (2015) Current strategies for reproductive management of gilts and sows in North America. Journal of Animal Science and Biotechnology 6, 3.
| Crossref | Google Scholar | PubMed |

Kvasnickii AV (2001) Research on interbreed ova transfer in pigs. Theriogenology 56, 1285-1289.
| Crossref | Google Scholar |

Li J, Rieke A, Day BN, Prather RS (1996) Technical note: porcine non-surgical embryo transfer. Journal of Animal Science 74, 2263-2268.
| Crossref | Google Scholar | PubMed |

Martinez EA, Vazquez JM, Roca J, Lucas X, Gil MA, Parrilla I, Vazquez JL, Day BN (2001) Successful non-surgical deep intrauterine insemination with small numbers of spermatozoa in sows. Reproduction 122, 289-296.
| Crossref | Google Scholar | PubMed |

Martinez EA, Caamaño JN, Gil MA, Rieke A, McCauley TC, Cantley TC, Vazquez JM, Roca J, Vazquez JL, Didion BA, Murphy CN, Prather RS, Day BN (2004) Successful nonsurgical deep uterine embryo transfer in pigs. Theriogenology 61, 137-146.
| Crossref | Google Scholar | PubMed |

Martinez EA, Gil MA, Cuello C, Sanchez-Osorio J, Gomis J, Parrilla I, Angel MA, Rodriguez-Martinez H, Lucas X, Vazquez JL, Vazquez JM, Roca J (2013) Current progress in non-surgical embryo transfer with fresh and vitrified/warmed pig embryos. Control of Pig Reproduction IX 101-112.
| Crossref | Google Scholar |

Martinez EA, Angel MA, Cuello C, Sanchez-Osorio J, Gomis J, Parrilla I, Vila J, Colina I, Diaz M, Reixach J, Vazquez JL, Vazquez JM, Roca J, Gil MA (2014) Successful non-surgical deep uterine transfer of porcine morulae after 24 hour culture in a chemically defined medium. PLoS ONE 9, e104696.
| Crossref | Google Scholar |

Martinez EA, Martinez CA, Nohalez A, Sanchez-Osorio J, Vazquez JM, Roca J, Parrilla I, Gil MA, Cuello C (2015) Nonsurgical deep uterine transfer of vitrified, in vivo-derived, porcine embryos is as effective as the default surgical approach. Scientific Reports 5, 1-9.
| Crossref | Google Scholar |

Martinez EA, Cuello C, Parrilla I, Martinez CA, Nohalez A, Vazquez JL, Vazquez JM, Roca J, Gil MA (2016a) Recent advances toward the practical application of embryo transfer in pigs. Theriogenology 85, 152-161.
| Crossref | Google Scholar | PubMed |

Martinez EA, Nohalez A, Martinez CA, Parrilla I, Vila J, Colina I, Diaz M, Reixach J, Vazquez JL, Roca J, Cuello C, Gil MA (2016b) The recipients’ parity does not influence their reproductive performance following non-surgical deep uterine porcine embryo transfer. Reproduction in Domestic Animals 51, 123-129.
| Crossref | Google Scholar | PubMed |

Martinez CA, Nohalez A, Parrilla I, Vazquez JL, Roca J, Cuello C, Rodriguez-Martinez H, Martinez EA, Gil MA (2017) Surgical embryo collection but not nonsurgical embryo transfer compromises postintervention prolificacy in sows. Theriogenology 87, 316-320.
| Crossref | Google Scholar | PubMed |

Martinez EA, Martinez CA, Cambra JM, Maside C, Lucas X, Vazquez JL, Vazquez JM, Roca J, Rodriguez-Martinez H, Gil MA, Parrilla I, Cuello C (2019) Achievements and future perspectives of embryo transfer technology in pigs. Reproduction in Domestic Animals 54, 4-13.
| Crossref | Google Scholar |

Martinez CA, Ruber M, Rodriguez-Martinez H, Alvarez-Rodriguez M (2020) Pig pregnancies after transfer of allogeneic embryos show a dysregulated endometrial/placental cytokine balance: a novel clue for embryo death? Biomolecules 10, 554.
| Crossref | Google Scholar |

Martinez CA, Alvarez-Rodriguez M, Rodriguez-Martinez H (2022) A decreased expression of interferon stimulated genes in peri-implantation endometrium of embryo transfer recipient sows could contribute to embryo death. Animal 16, 100590.
| Crossref | Google Scholar | PubMed |

Miles JR, Freking BA, Blomberg LA, Vallet JL, Zuelke KA (2008) Conceptus development during blastocyst elongation in lines of pigs selected for increased uterine capacity or ovulation rate. Journal of Animal Science 86, 2126-2134.
| Crossref | Google Scholar | PubMed |

Nakazawa Y, Misawa H, Fujino Y, Tajima S, Misumi K, Ueda J, Nakamura Y, Shibata T, Hirayama Y, Kikuchi K (2008) Effect of volume of non-surgical embryo transfer medium on ability of porcine embryos to survive to term. Journal of Reproduction and Development 54, 30-34.
| Crossref | Google Scholar | PubMed |

Niemann H, Wüst A, Gardon JC (1989) Successful intercontinental transport of porcine embryos from Europe to South America. Theriogenology 31, 525-530.
| Crossref | Google Scholar | PubMed |

Nohalez A, Martinez CA, Reixach J, Diaz M, Vila J, Colina I, Parrilla I, Vazquez JL, Roca J, Gil MA, Rodriguez-Martinez H, Martinez EA, Cuello C (2017) Factors of importance when selecting sows as embryo donors. Animal 11, 1330-1335.
| Crossref | Google Scholar | PubMed |

Okuyama MW, Sugiura T, Moriyoshi M, Yamashita K, Tamura J, Katagiri S (2017) A transvaginal endoscopy-based technique for performing ovarian examinations in sows. Journal of Reproduction and Development 63, 617-622.
| Crossref | Google Scholar | PubMed |

Oltedal A, Björkman S, Peltoniemi O, Gaustad AH, Oropeza-Moe M (2024a) Transvaginal ovum pick-up in sows: impacts on welfare and reproduction. Theriogenology 226, 68-75.
| Crossref | Google Scholar | PubMed |

Oltedal A, Gaustad AH, Peltoniemi O, Björkman S, Skaare A, Oropeza-Moe M (2024b) Experiences with transvaginal Ovum Pick-Up (OPU) in sows. Theriogenology 214, 157-165.
| Crossref | Google Scholar | PubMed |

Parrilla I, Gil MA, Cuello C, Cambra JM, Gonzalez-Plaza A, Lucas X, Vazquez JL, Vazquez JM, Rodriguez-Martinez H, Martinez EA (2022) Immunological uterine response to pig embryos before and during implantation. Reproduction in Domestic Animals 57(Suppl 5), 4-13.
| Crossref | Google Scholar | PubMed |

Polge C (1982) Embryo transplantation and preservation. In ‘Control of pig reproduction’. (Eds D Cole, G Foxcroft) pp. 277–291. (Butterworth: London, UK)

Polge C, Day B (1968) Pregnancy following non-surgical egg transfer in pigs. Veterinary Record 82, 712.
| Google Scholar |

Pope WF (1994) Embryonic mortality in swine. In ‘Embryonic mortality in domestic species’. (Eds M Zavy, R Geisert) pp. 53–77. (CRC Press: Boca Raton, FL, USA)

Reichenbach HD, Mödl J, Brem G (1993) Piglets born after transcervical transfer of embryos into recipient gilts. Veterinary Record 133, 36-39.
| Crossref | Google Scholar | PubMed |

Roca J, Parrilla I, Bolarin A, Martinez EA, Rodriguez-Martinez H (2016) Will AI in pigs become more efficient? Theriogenology 86, 187-193.
| Crossref | Google Scholar | PubMed |

Sanchez-Osorio J, Cuello C, Gil MA, Almiñana C, Parrilla I, Caballero I, Garcia EM, Vazquez JM, Roca J, Martinez EA, Alminana C, Parrilla I, Caballero I, Garcia EM, Vazquez JM, Roca J, Martinez EA (2008) Factors affecting the success rate of porcine embryo vitrification by the open pulled straw method. Animal Reproduction Science 108, 334-344.
| Crossref | Google Scholar | PubMed |

Spötter A, Distl O (2006) Genetic approaches to the improvement of fertility traits in the pig. The Veterinary Journal 172, 234-247.
| Crossref | Google Scholar | PubMed |

Tajima S, Motoyama S, Wakiya Y, Uchikura K, Misawa H, Takishita R, Hirayama Y, Kikuchi K (2020) Piglet production by non-surgical transfer of vitrified embryos, transported to commercial swine farms and warmed on site. Animal Science Journal 91, e13476.
| Crossref | Google Scholar | PubMed |

Vallet JL, Freking BA, Miles JR (2011) Effect of empty uterine space on birth intervals and fetal and placental development in pigs. Animal Reproduction Science 125, 158-164.
| Crossref | Google Scholar | PubMed |

Wallenhorst S, Holtz W (1999) Transfer of pig embryos to different uterine sites. Journal of Animal Science 77, 2327-2329.
| Crossref | Google Scholar | PubMed |

Whitworth KM, Lee K, Benne JA, Beaton BP, Spate LD, Murphy SL, Samuel MS, Mao J, O’Gorman C, Walters EM, Murphy CN, Driver J, Mileham A, McLaren D, Wells KD, Prather RS (2014) Use of the CRISPR/Cas9 system to produce genetically engineered pigs from in vitro-derived oocytes and embryos. Biology of Reproduction 91, 78.
| Crossref | Google Scholar | PubMed |

Wilson ME, Biensen NJ, Youngs CR, Ford SP (1998) Development of Meishan and Yorkshire littermate conceptuses in either a Meishan or Yorkshire uterine environment to day 90 of gestation and to term. Biology of Reproduction 58, 905-910.
| Crossref | Google Scholar | PubMed |

Wolf E, Arnold GJ, Bauersachs S, Beier HM, Blum H, Einspanier R, Fröhlich T, Herrler A, Hiendleder S, Kölle S, Prelle K, Reichenbach H-D, Stojkovic M, Wenigerkind H, Sinowatz F (2003) Embryo-maternal communication in bovine – strategies for deciphering a complex cross-talk. Reproduction in Domestic Animals 38, 276-289.
| Crossref | Google Scholar | PubMed |

Wulster-Radcliffe MC, Seals RC, Lewis GS (2003) Progesterone increases susceptibility of gilts to uterine infections after intrauterine inoculation with infectious bacteria. Journal of Animal Science 81, 1242-1252.
| Crossref | Google Scholar | PubMed |

Xingzhu D, Qingrui Z, Keren C, Yuxi L, Yunpeng H, Shien Z, Xiangwei F (2021) Cryopreservation of porcine embryos: recent updates and progress. Biopreservation and Biobanking 19, 210-218.
| Crossref | Google Scholar | PubMed |

Yoshioka K, Noguchi M, Suzuki C (2012) Production of piglets from in vitro-produced embryos following non-surgical transfer. Animal Reproduction Science 131, 23-29.
| Crossref | Google Scholar | PubMed |

Yoshioka K, Uchikura K, Suda T, Matoba S (2020) Production of piglets from in vitro-produced blastocysts by ultrasound-guided ovum pick-up from live donors. Theriogenology 141, 113-119.
| Crossref | Google Scholar | PubMed |

Zou Y, Li Z, Zou Y, Hao H, Li N, Li Q (2018) An FBXO40 knockout generated by CRISPR/Cas9 causes muscle hypertrophy in pigs without detectable pathological effects. Biochemical and Biophysical Research Communications 498, 940-945.
| Crossref | Google Scholar | PubMed |