{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,3]],"date-time":"2026-02-03T16:37:17Z","timestamp":1770136637672,"version":"3.49.0"},"reference-count":31,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,2,3]],"date-time":"2026-02-03T00:00:00Z","timestamp":1770076800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Vet. Sci."],"abstract":"<jats:p>\n                    This article presents an overview of the update on direct embryo transfer using hatched blastocysts. Recent research has observed differences in conception rates in sheep following surgical transfer. All sessions included in the study followed the same standard protocol, resulting in the creation of two groups, with the control group (CG) being the one in which blastocysts were transferred, and the experimental group (EG) received hatched blastocysts. Embryos were obtained from meat sheep through\n                    <jats:italic>in vivo<\/jats:italic>\n                    derived (IVD) and transferred to crossbred sheep synchronized with very obvious corpus luteum (CL) on at least one of the ovaries (84.21%). Thus, a retrospective study highlights the clear success of embryo recipients who also received hatched blastocysts (code 9.1) compared to recipients with blastocysts only (code 6.1, 7.1). The embryo recovery rate at 6.5\u202fdays, determined by laparoscopic uterine flushing, was 84.3%. In terms of the quality of the embryos obtained, over 74.5% were transferable (not statistically significant, 76.6% in Suffolk and 72.3% in Ille de France), and over 12% of the embryos hatched. The study found that the pregnancy rate in recipient ewes receiving code 9.1 embryos (expanded blastocysts) through direct IVD transfer during the breeding season was 86.9%. These findings, when compared to previous research, highlight the potential for further exploration and innovation in this area. Nonetheless, it is important to note that there is a scarcity of literature addressing the direct transfer of IVD embryos with expanded blastocysts.\n                  <\/jats:p>","DOI":"10.3389\/fvets.2026.1778321","type":"journal-article","created":{"date-parts":[[2026,2,3]],"date-time":"2026-02-03T05:22:04Z","timestamp":1770096124000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Update on direct embryo transfer in sheep: hatched blastocysts increase conception rates"],"prefix":"10.3389","volume":"13","author":[{"given":"\u0218tefan Gregore","family":"Ciornei","sequence":"first","affiliation":[{"name":"Embryo Technology Laboratory, Faculty of Veterinary Medicine, \"Ion Ionescu de la Brad\" Iasi University of Life Sciences","place":["Iasi, Romania"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,2,3]]},"reference":[{"key":"ref1","doi-asserted-by":"crossref","DOI":"10.1007\/978-3-319-92327-7_6","article-title":"ET-Technologies in Small Ruminants","volume-title":"Animal biotechnology 1","author":"Ledda","year":"2018"},{"key":"ref2","first-page":"517","article-title":"Comparative data about estrus induction and pregnancy rate on Lacaune ewes in non-breeding season after melatonin implants and intravaginal progestagen","volume-title":"Indian Journal of Animal Research","author":"Berean","year":"2021"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"128","DOI":"10.1016\/j.smallrumres.2007.09.002","article-title":"Effect of anti-oxidants and oxidative stress parameters on ram semen after the freeze\u2013thawing process","volume":"75","author":"Bucak","year":"2008","journal-title":"Small Rumin Res"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"1558641","DOI":"10.3389\/fvets.2025.1558641","article-title":"Editorial: reproductive biotechnologies and challenges in their application","volume":"12","author":"Ciornei","year":"2025","journal-title":"Front Vet Sci"},{"key":"ref5","first-page":"312","article-title":"Echilibrul fiziologic al organismuli \u00een func\u021bie de influen\u021ba stresului termic","volume-title":"Fiziologia \u015fi s\u0103n\u0103tatea","author":"Moroz","year":"2024"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"144","DOI":"10.1016\/j.theriogenology.2016.04.025","article-title":"Nonsurgical embryo recovery and transfer in sheep and goats","volume":"86","author":"Fonseca","year":"2016","journal-title":"Theriogenology"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"84","DOI":"10.1016\/j.smallrumres.2014.04.002","article-title":"Repeatability of superovulatory response to successive FSH treatment in merino sheep","volume":"120","author":"Bruno-Galarraga","year":"2014","journal-title":"Small Rumin Res"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"1376794","DOI":"10.3389\/fvets.2024.1376794","article-title":"Perspectives in the biotechnology of artificial insemination in ruminants","volume":"11","author":"Ciornei","year":"2024","journal-title":"Front Vet Sci"},{"key":"ref9","first-page":"139","author":"Mircu","year":"2020"},{"key":"ref10","first-page":"n.4","article-title":"IETS Data Retrieval Committee","volume":"38","author":"Viana","year":"2020","journal-title":"Embryo Technology Newsletter"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"183","DOI":"10.1017\/S0003356100011648","article-title":"The survival of embryos transferred in large groups to sheep of breeds with different ovulation rates","volume":"24","author":"Land","year":"1977","journal-title":"Anim Sci"},{"key":"ref12","first-page":"190","author":"Ciornei","year":"2021"},{"key":"ref13","first-page":"1345","author":"Alabart","year":"2003"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1111\/rda.14127","article-title":"Embryo biotechnologies in sheep: achievements and new improvements","volume":"57","author":"Falchi","year":"2022","journal-title":"Reprod Domest Anim"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"2","DOI":"10.5772\/intechopen.99683","article-title":"Embryo Transfer","author":"Ciornei","year":"2022","journal-title":"IntechOpen"},{"key":"ref16","article-title":"SOP for small ruminant embryo technology","volume-title":"Part 1: In vivo embryo production","year":""},{"key":"ref17","doi-asserted-by":"publisher","first-page":"522","DOI":"10.1136\/vr.159.16.522","article-title":"Production of prolific microsheep by embryo transfer into large non-prolific sheep","volume":"159","author":"Naqvi","year":"2006","journal-title":"Vet Rec"},{"key":"ref18","doi-asserted-by":"publisher","first-page":"8","DOI":"10.1111\/j.1439-0531.2008.01200.x","article-title":"Effect of inter-breed embryo transfer on lamb growing performance and survival","volume":"47","author":"Emsen","year":"2012","journal-title":"Reprod Domest Anim"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"52","DOI":"10.2527\/1998.76suppl_352x","article-title":"The current status of oocyte recovery, in vitro embryo production, and embryo transfer in domestic animals, with an emphasis on the Bovine1","volume":"76","author":"Hasler","year":"1998","journal-title":"J Anim Sci"},{"key":"ref20","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1093\/oxfordjournals.humrep.a137542","article-title":"The cumulative embryo score: a predictive embryo scoring technique to select the optimal number of embryos to transfer in an in-vitro fertilization and embryo transfer programme","volume":"7","author":"Steer","year":"1992","journal-title":"Hum Reprod"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"1265060","DOI":"10.3389\/fvets.2023.1265060","article-title":"Upgrading the fixed-time artificial insemination (FTAI) protocol in Romanian buffaloes","volume":"10","author":"Ciornei","year":"2023","journal-title":"Front Vet Sci"},{"key":"ref22","doi-asserted-by":"crossref","first-page":"451","DOI":"10.1111\/avj.13174","article-title":"Multiple ovulation and embryo transfer in sheep: effects of embryo developmental stage and quality on viability in vivo under farm conditions","volume":"100","author":"King","year":"2022","journal-title":"Aust Vet J"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"726","DOI":"10.1002\/vms3.705","article-title":"Ovarian response to P4-PGF-FSH treatment in Suffolk sheep and P4-PGF-PMSG synchronization in cross-bred ewes, for IVD and ET protocol","volume":"8","author":"Ciornei","year":"2022","journal-title":"Vet Med Sci"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"74","DOI":"10.1007\/s43032-024-01499-7","article-title":"In vitro fertilization outcomes of frozen\u2013thawed embryo transfer with hatched blastocysts versus with hatching blastocysts","volume":"32","author":"Kim","year":"2025","journal-title":"Reprod Sci"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"477","DOI":"10.1016\/j.theriogenology.2009.04.002","article-title":"Progesterone treatment, FSH plus eCG, GnRH administration, and day 0 protocol for MOET programs in sheep","volume":"72","author":"Menchaca","year":"2009","journal-title":"Theriogenology"},{"key":"ref26","doi-asserted-by":"publisher","first-page":"1442931","DOI":"10.3389\/fvets.2024.1442931","article-title":"Metabolomics analysis of the effect of GnRH on the pregnancy rate of ewes with estrus synchronization scheme based on progesterone","volume":"11","author":"Zhang","year":"2024","journal-title":"Front Vet Sci"},{"key":"ref27","doi-asserted-by":"publisher","first-page":"177","DOI":"10.1530\/JOE-19-0349","article-title":"Progesterone-regulated Hsd11b2 as a barrier to balance mouse uterine corticosterone","volume":"244","author":"Zheng","year":"2020","journal-title":"J Endocrinol"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"680539","DOI":"10.3389\/fvets.2021.680539","article-title":"Lineage differentiation markers as a proxy for embryo viability in farm ungulates","volume":"8","author":"P\u00e9rez-G\u00f3mez","year":"2021","journal-title":"Front Vet Sci"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"67","DOI":"10.1071\/RD09214","article-title":"Bovine embryo transfer recipient synchronisation and management in tropical environments","volume":"22","author":"Baruselli","year":"2009","journal-title":"Reprod Fertil Dev"},{"key":"ref30","doi-asserted-by":"crossref","first-page":"1511","DOI":"10.1016\/S0093-691X(00)00293-4","article-title":"Surviv land viability of vitrified in vitro and in vivo produced ovine blastocysts","volume":"53","author":"Dattena","year":"2000","journal-title":"Theriogenology"},{"key":"ref31","doi-asserted-by":"publisher","first-page":"35","DOI":"10.1016\/S0378-4320(02)00162-8","article-title":"Embryo survival and recipient pregnancy rates after transfer of fresh or vitrified, in vivo or in vitro produced ovine blastocysts","volume":"74","author":"Papadopoulos","year":"2002","journal-title":"Anim Reprod Sci"}],"container-title":["Frontiers in Veterinary Science"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fvets.2026.1778321\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,3]],"date-time":"2026-02-03T05:22:05Z","timestamp":1770096125000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fvets.2026.1778321\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,3]]},"references-count":31,"alternative-id":["10.3389\/fvets.2026.1778321"],"URL":"https:\/\/doi.org\/10.3389\/fvets.2026.1778321","relation":{},"ISSN":["2297-1769"],"issn-type":[{"value":"2297-1769","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,3]]},"article-number":"1778321"}}