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Communication Dans Un Congrès Année : 2013

Transcervical embryo collection in late stage in cattle

Résumé

Transcervical embryo collection is used routinely in the bovine species throughout the world to collect D6 to D9 embryos (Early embryos) for genetic selection. For research purposes, however, the collection of embryos at later stages of pregnancy, i.e., D12 to D21 (late embryos), is needed. So far, for the recovery of late embryos, females are euthanized and embryo collection is performed after recovery of the genital tract. In order to reduce the number of animals used and still provide valuable material for embryo research, we have therefore developed a transcervical technique to collect late embryos. The objective of this study was to compare embryo recovery results at early and late stages within our laboratory. Altogether, 232 cows were used for this study. 145 flushes were performed to collect D6-D9 embryos and 251 flushes were performed to collect D12 to D21 embryos. For the early embryos, a classical 3 way collection equipment (IMV, France) was used. To collect the late embryos, the same equipment was used but the extensible flexible catheter that goes inside the external rigid catheter was removed, so that larger embryos could be collected through the remaining larger hole (2 way collection). All females were submitted to ovum pick-up to remove the dominant follicle and were subsequently superovulated with FSH (Stimufol®, Reprobiol). Luteolysis was induced 48 hours prior to AI. Two AI were performed with frozen semen, 48 and 56 hours after PGF2 injection. Before embryo collection, cows were treated with an epidural injection of 3-4 ml Lidocaine®. The presence of copora lutea (CL) was checked and they were counted by rectal palpation. For all collections, the cervix was prepared with the initial introduction of a dilator. Then the catheter was introduced in one horn and the cuff was inflated as low as possible. For the collection of late embryos, 30 ml (Euroflush, IMV) was injected slowly twice to suspend the embryos prior to flushing the horn with 500 ml, and the same operation was performed on the second horn. There was no significant difference in the number of embryos collected per flush in the early and late stages (758 embryos collected, 5.22 ±6.02 per flush vs 1238 embryos collected, 4.93 ±5.07 per flush, respectively). The number of embryos collected per corpus luteum, however, was significantly lower in the early vs late group (0.39% ±0.32 vs 0.44% ±0.34, respectively). Late collection allowed the retrieval of full embryos (Inner Cell Mass + trophoblast), even at very late stages such as D18 to D21. Careful collection is needed, however, so that embryonic tissues are not damaged or torn: the horn must be massaged gently and the flush should be ideally recovered in one single flow. This technique is a powerful tool to collect late stage embryos for research purposes. It can also be applied to recover single embryos after AI or ET. Since it is not traumatic, animals can be used again for the same procedure.
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Dates et versions

hal-01019550 , version 1 (07-07-2014)

Identifiants

  • HAL Id : hal-01019550 , version 1
  • PRODINRA : 243980

Citer

Christophe Richard, Valerie Gelin, Alexandre Neveux, Isabelle Hue, Yvan Heyman, et al.. Transcervical embryo collection in late stage in cattle. 29. Annual Meeting AETE 2013, Association Européenne de Transfert Embryonnaire - European Embryo Transfer Association (AETE). FRA., Sep 2013, Istanbul, Turkey. pp.194. ⟨hal-01019550⟩
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