title: An earlier uterine environment favors the in vivo development of fresh pig morulae and blastocysts transferred by a nonsurgical deep-uterine method.
abstract: This study aimed to evaluate the effect of recipient-donor estrous cycle synchrony on recipient reproductive performance after nonsurgical deep-uterine (NsDU) embryo transfer (ET). The transfers (N=132) were conducted in recipients sows that started estrus 24 h before (-24 h; N=9) or 0 h (synchronous; N=31), 24 h (+24 h; N=74) or 48 h (+48 h; N=18) after the donors. A total of 30 day 5 morulae or day 6 blastocysts (day 0=onset of estrus) were transferred per recipient. The highest farrowing rates (FRs) were achieved when estrus appeared in recipients 24 h later than that in the donors (81.1%), regardless of the embryonic stage used for the transfers. The FR notably decreased (P<0.05) when recipients were -24 h asynchronous (0%), synchronous (61.3%) or +48 h asynchronous (50%) relative to the donors. No differences in litter size (LS) and piglet birth weights were observed among the synchronous and +24 h or +48 h asynchronous groups. While a +24 h asynchronous recipient was suitable for transfers performed with either morulae (FR, 74.3%; LS, 9.2 ± 0.6 piglets) or blastocysts (FR, 84.6%; LS, 9.8 ± 0.6 piglets), a + 48 h asynchronous recipient was adequate for blastocysts (FR, 87.5%; LS, 10.4 ± 0.7 piglets) but not for morulae (FR, 30.0%; LS, 7.3 ± 2.3 piglets). In conclusion, this study confirms the effectiveness of the NsDU-ET technology and shows that porcine embryos tolerate better a less advanced uterine environment if they are nonsurgically transferred deep into the uterine horn.
authors.affiliation: Department of Animal Medicine and Surgery, University of Murcia, Espinardo 30100, Spain.
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Angel
authors.forename: Maria Antonia
authors.initials: MA
authors.lastname: Gil
authors.forename: Cristina
authors.initials: C
authors.lastname: Cuello
authors.forename: Jonatan
authors.initials: J
authors.lastname: Sanchez-Osorio
authors.forename: Jesus
authors.initials: J
authors.lastname: Gomis
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Parrilla
authors.forename: Jordi
authors.initials: J
authors.lastname: Vila
authors.forename: Ignacio
authors.initials: I
authors.lastname: Colina
authors.forename: Marta
authors.initials: M
authors.lastname: Diaz
authors.forename: Josep
authors.initials: J
authors.lastname: Reixach
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Vazquez
authors.forename: Juan Maria
authors.initials: JM
authors.lastname: Vazquez
authors.forename: Jordi
authors.initials: J
authors.lastname: Roca
authors.forename: Emilio A
authors.initials: EA
authors.lastname: Martinez
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D004624:Embryo Transfer / Q000379:methods / Q000662:veterinary*; D047108:Embryonic Development / Q000502:physiology*; D004971:Estrus / Q000502:physiology*; D004973:Estrus Synchronization / Q000502:physiology; D005260:Female; D009028:Morula / Q000502:physiology; D011247:Pregnancy; D034421:Sus scrofa; D014599:Uterus / Q000502:physiology*