PMID- 35582817
OWN - NLM
STAT- MEDLINE
DCOM- 20220907
LR  - 20221015
IS  - 1751-0813 (Electronic)
IS  - 0005-0423 (Print)
IS  - 0005-0423 (Linking)
VI  - 100
IP  - 9
DP  - 2022 Sep
TI  - Multiple ovulation and embryo transfer in sheep: Effects of embryo developmental 
      stage and quality on viability in vivo under farm conditions.
PG  - 451-458
LID - 10.1111/avj.13174 [doi]
AB  - Multiple ovulation and embryo transfer (MOET) technologies are integral to 
      genetic improvement programs in the sheep industries. Despite the protocols being 
      well established, previous findings regarding the effects of embryo properties on 
      MOET success remain contradictory. The objective of this study was to determine 
      the effects of embryo developmental stage and quality on embryo viability 
      following transfer to recipient ewes. Data including details of 377 embryos 
      collected from 45 Merino donor ewes were obtained from MOET trials conducted on 
      three separate farms on day 6 after laparoscopic artificial insemination (AI). A 
      total of 270 embryos were classified as being of transferrable grade (grade 1: 
      n = 233; grade 2: n = 37). One or two transferrable grade embryos were 
      transferred to each of 256 synchronised recipient ewes and pregnancy diagnosis 
      was performed on day 36 after embryo transfer. Embryos at the hatched blastocyst 
      stage tended to have greater viability in vivo compared to embryos at the late 
      morula stage (59.0 +/- 10.6% vs. 36.2 +/- 9.7%; P = 0.083). The viability of grade 1 
      embryos was greater than that of grade 2 embryos (53.6 +/- 7.8% vs. 35.9 +/- 10.2%; 
      P < 0.05). The results suggest that the success of the MOET trials was influenced 
      by the transfer of embryos at the late morula stage, almost half of which were 
      classified as grade 2 embryos. These findings highlight the importance of 
      following strict embryo quality grading criteria to inform the most economical 
      management of recipient ewes and maximize pregnancy outcomes.
CI  - (c) 2022 The Authors. Australian Veterinary Journal published by John Wiley & Sons 
      Australia, Ltd on behalf of Australian Veterinary Association.
FAU - King, Caf
AU  - King C
AD  - Sydney School of Veterinary Science, Faculty of Science, The University of 
      Sydney, Camden, New South Wales, 2570, Australia.
FAU - Osborn, D
AU  - Osborn D
AD  - Apiam Genetic Services, Dubbo, New South Wales, 2830, Australia.
FAU - Grupen, C G
AU  - Grupen CG
AUID- ORCID: 0000-0001-8352-0404
AD  - Sydney School of Veterinary Science, Faculty of Science, The University of 
      Sydney, Camden, New South Wales, 2570, Australia.
LA  - eng
PT  - Journal Article
DEP - 20220518
PL  - England
TA  - Aust Vet J
JT  - Australian veterinary journal
JID - 0370616
SB  - IM
MH  - Animals
MH  - *Embryo Transfer/veterinary
MH  - Farms
MH  - Female
MH  - *Insemination, Artificial/veterinary
MH  - Ovulation
MH  - Pregnancy
MH  - Sheep
PMC - PMC9543396
OTO - NOTNLM
OT  - embryo transfer
OT  - embryonic development
OT  - ovine
OT  - superovulation
COIS- The authors declare no conflicts of interest or sources of funding for the work 
      presented here.
EDAT- 2022/05/19 06:00
MHDA- 2022/09/08 06:00
PMCR- 2022/10/07
CRDT- 2022/05/18 03:22
PHST- 2022/04/25 00:00 [revised]
PHST- 2021/12/30 00:00 [received]
PHST- 2022/05/04 00:00 [accepted]
PHST- 2022/05/19 06:00 [pubmed]
PHST- 2022/09/08 06:00 [medline]
PHST- 2022/05/18 03:22 [entrez]
PHST- 2022/10/07 00:00 [pmc-release]
AID - AVJ13174 [pii]
AID - 10.1111/avj.13174 [doi]
PST - ppublish
SO  - Aust Vet J. 2022 Sep;100(9):451-458. doi: 10.1111/avj.13174. Epub 2022 May 18.