243 Importance of sheep pre-selection based on cervical anatomy for the efficiency of non-surgical embryo recovery
J. Dias A , G. Vergani B , J. Gonçalves B , T. Oliveira C , R. Batista C , J. Souza-Fabjan C , M. E. Oliveira B and J. Fonseca DA Universidade Federal de Viçosa, Viçosa, MG, Brazil
B Universidade Estadual Paulista, Jaboticabal, SP, Brazil
C Universidade Federal Fluminense, Niterói, RJ, Brazil
D Embrapa Caprinos e Ovinos, Sobral, CE, Brazil
Reproduction, Fertility and Development 35(2) 251-251 https://doi.org/10.1071/RDv35n2Ab243
Published: 5 December 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
Non-surgical embryo recovery (NSER) is a transcervical technique for embryo collection and a less invasive alternative to laparotomy. The NSER procedure is based on two successive cervical transpositions: first, by using a Hegar dilator, which allows for the observation of the cervical alignment and improves cervical dilation; and second, the mandrel-catheter device, through which uterine flushing occurs. In general, NSER is impaired by a high degree of cervical misalignment (which often does not allow their transposition) or by anatomical characteristics that prevent correct cervical clamping. This study reports the importance of selecting animals according to their cervical anatomy before NSER. 38 superovulated White Dorper ewes of unknown parturition history and cervical anatomy were submitted to NSER (Dias et al. 2020 Reprod. Domest. Anim. 55, 844–50). NSER was successfully performed (cervical transpositions with both Hegar dilator and mandrel-catheter) in 60.5% (23/38) of animals, and the overall recovery rate was 45.4 ± 6.2%. Unsuccessful cervical transposition by Hegar dilator occurred in 31.6% (12/38) and by mandrel-catheter in 7.9% (3/38) of the animals, for reasons that included vestibulo-vaginal stenosis (13/15; 76.7%) and low cervical retraction (2/15; 13.3%). These data highlight that NSER failure is strongly correlated with cervical abnormalities. Of note, previous studies with the same cervical relaxation protocol allowed cervical transposition in 80–90% of the selected ewes (Dias et al., 2020), showing that the non-selection of animals may considerably reduce the overall NSER efficiency. In conclusion, the NSER failure by cervical abnormalities can be avoided through a previous transposition of the animals with Hegar dilator at the donor pre-selection step, both to avoid losses in the feasibility of the technique and unnecessary costs with hormonal protocols.
This research was supported by Embrapa (22.13.06.026.00.04) and Fapemig (CVZ-PPM 00201-17).
