title: Nonsurgical deep uterine transfer of vitrified, in vivo-derived, porcine embryos is as effective as the default surgical approach.
abstract: Surgical procedures are prevalent in porcine embryo transfer (ET) programs, where the use of vitrified embryos is quasi non-existent. This study compared the effectiveness of surgical vs nonsurgical deep uterine (NsDU) ET using vitrified, in vivo-derived embryos (morulae and blastocysts) on the reproductive performance and welfare of the recipients. The recipient sows (n=122) were randomly assigned to one of the following groups: surgical ET with 30 vitrified-warmed embryos (S-30 group, control); NsDU-ET with 30 vitrified-warmed embryos (NsDU-30 group) and NsDU-ET with 40 vitrified-warmed embryos (NsDU-40 group). Regardless of embryo stage, the NsDU-ET with 40 embryos presented similar rates of farrowing (72.7%) and litter size (9.9 ± 2.1 piglets) as the customary surgical procedure (75.0% and 9.6 ± 2.7 piglets). Numbers of ET-embryos appeared relevant, since the NsDU-ET with 30 embryos resulted in a decrease (P<0.05) in farrowing rates (38.9%) and litter sizes (5.7 ± 2.4 piglets). In conclusion, we demonstrate for the first time that farrowing rate and litter size following a NsDU-ET procedure increase in function of a larger number of transferred vitrified embryos, with fertility equalizing that obtained with the invasive surgical approach. The results open new possibilities for the widespread use of non-invasive ET in pigs.
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Spain.
authors.forename: Emilio A
authors.initials: EA
authors.lastname: Martinez
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Spain.
authors.forename: Cristina A
authors.initials: CA
authors.lastname: Martinez
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Nohalez
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Spain.
authors.forename: Jonatan
authors.initials: J
authors.lastname: Sanchez-Osorio
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Vazquez
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Roca
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Parrilla
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Spain.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Gil
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Cuello
mesh_terms: D000818:Animals; D046149:Embryo Culture Techniques; D004624:Embryo Transfer / Q000379:methods*; D012098:Reproduction; D013552:Swine