Analyze Diet
Veterinary journal (London, England : 1997)2011; 192(3); 322-325; doi: 10.1016/j.tvjl.2011.06.036

Manual reduction of multiple embryos in the mare: the effect on subsequent pregnancy outcome.

Abstract: To determine whether manually reduced multiple pregnancies (MPs) are at a greater risk of pregnancy loss than single pregnancy (SP) in mares, and to examine if a difference exists in the timing of pregnancy loss between manually reduced MPs and SPs, 1916 Thoroughbred mares were ultrasonically monitored every 2 days during oestrus to confirm ovulation, and up to Day 40 post-ovulation to confirm pregnancy. Ultimate pregnancy outcome was ascertained from the General Thoroughbred Stud book and classified as live foal (LF), early abortion (EA; Days 40-150), slipped foal (SF; Days 150-term), and barren (B; Time of pregnancy loss unknown). Significantly (P<0.05) more SPs failed (17.23%; 226/1312) than manually reduced MPs (13.41%; 81/604). Both SPs and MPs were at greatest risk of being lost as EA (72.16%; 127/176 and 61.67%; 37/60, respectively) compared to SF (27.84%; 49/176 and 38.33%; 23/60). There was no significant difference in the time of greatest risk of pregnancy loss between manually reduced MPs and SPs. It was concluded that owners and veterinarians can be assured that manual reduction of MPs does not increase the risk of pregnancy loss above those associated with SPs.
Publication Date: 2011-10-13 PubMed ID: 22000782DOI: 10.1016/j.tvjl.2011.06.036Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research paper examines the effects of manual reduction on multiple pregnancies in mares, specifically looking at the risk of pregnancy loss in comparison to single pregnancies. The study monitored 1,916 Thoroughbred mares and found no significant difference in the risk of pregnancy loss between manually reduced multiple pregnancies and single pregnancies.

Study Design and Methodology

  • The researchers examined the pregnancies of 1,916 Thoroughbred mares, comparing single pregnancies to multiple pregnancies that had been reduced manually.
  • Mares were ultrasonically monitored every two days during oestrus (the period of sexual receptivity in female mammals) to confirm ovulation, and this monitoring continued up till Day 40 post-ovulation to confirm pregnancy.
  • The final pregnancy outcome was classified based on guidelines from the General Thoroughbred Stud book defining whether the pregnancy resulted in a live foal, early abortion, slipped foal, or was barren.

Pregnancy Outcomes

  • A significant finding was that more single pregnancies failed (17.23% or 226 out of 1,312) as compared to manually reduced multiple pregnancies (13.41% or 81 out of 604).
  • Both types of pregnancies, single and multiple, were found to be most likely lost during the early abortion period (72.16% of single pregnancies and 61.67% of multiple pregnancies) than the slipped foal stage (27.84% of single pregnancies and 38.33% of multiple pregnancies).
  • No significant difference was noted in the timing of the greatest risk of pregnancy loss between manually reduced multiple pregnancies and single pregnancies.

Conclusion

  • The results of this study conclude that manual reduction of multiple pregnancies in mares does not increase the risk of pregnancy loss compared to single pregnancies.
  • This study provides valuable reassurance to horse owners and veterinarians that manual reduction of multiple pregnancies is a viable and safe practice, presenting no additional risk of pregnancy loss to the mares.

Cite This Article

APA
Davies Morel MC, Newcombe JR, Lauber M. (2011). Manual reduction of multiple embryos in the mare: the effect on subsequent pregnancy outcome. Vet J, 192(3), 322-325. https://doi.org/10.1016/j.tvjl.2011.06.036

Publication

ISSN: 1532-2971
NlmUniqueID: 9706281
Country: England
Language: English
Volume: 192
Issue: 3
Pages: 322-325

Researcher Affiliations

Davies Morel, M C G
  • Aberystwyth University, Institute of Biological, Environmental and Rural Sciences, Aberystwyth, Ceredigion SY23 3AL, UK. mid@aber.ac.uk
Newcombe, J R
    Lauber, M

      MeSH Terms

      • Abortion, Veterinary / etiology
      • Animals
      • Embryo Implantation / physiology
      • Female
      • Horse Diseases / prevention & control
      • Horses
      • Pregnancy
      • Pregnancy Outcome / veterinary
      • Pregnancy Reduction, Multifetal / methods
      • Pregnancy Reduction, Multifetal / veterinary
      • Pregnancy, Animal
      • Pregnancy, Multiple
      • Risk Factors
      • Stillbirth / veterinary

      Citations

      This article has been cited 2 times.
      1. López-Gatius F, Garcia-Ispierto I. Sexing of Embryos at the Time of Twin Reduction: A Clinical Approach. Animals (Basel) 2023 Apr 12;13(8).
        doi: 10.3390/ani13081326pubmed: 37106889google scholar: lookup
      2. López-Gatius F. Twins in Dairy Herds. Is It Better to Maintain or Reduce a Pregnancy?. Animals (Basel) 2020 Oct 31;10(11).
        doi: 10.3390/ani10112006pubmed: 33142688google scholar: lookup