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Home / Equine Research Bank / Animals (Basel) / The Timing of the Maternal Recognition of Pregnancy Is Speci...
Animals : an open access journal from MDPI2023; 13(10); 1718; doi: 10.3390/ani13101718

The Timing of the Maternal Recognition of Pregnancy Is Specific to Individual Mares.

Abstract: The present experiment aimed at determining whether the timing of the maternal recognition of pregnancy (MRP) was specific to individual mares by determining when luteostasis, a failure to return to oestrus, reliably occurred in individuals following embryo reduction. Singleton (n = 150) and synchronous twin pregnancies (n = 9) were reduced in 10 individuals (5-29 reductions/mare) at pre-determined time points within days 10 (n = 20), 11 (n = 65), 12 (n = 47), 13 (n = 12) or 14 (n = 15) of pregnancy. Prior to embryo reduction, the vesicle diameter was measured in 71% (106/150) of the singleton pregnancies. The interovulatory interval (IOI) was recorded on 78 occasions in seven of the mares in either non-pregnant cycles (n = 37) or those in which luteolysis followed embryo reduction (n = 41). The earliest time post-ovulation at which the embryo reduction resulted in luteostasis in an individual was 252 h (mid-Day 10). Consistency in luteostasis following embryo reduction showed individual variation between mares (272-344 h). Binary logistic regression analysis showed an individual mare effect ( < 0.001) and an effect of the interval post-ovulation at which embryo reduction was undertaken ( < 0.001). However, there was no significant effect of vesicle diameter at the time of embryo reduction ( = 0.099), nor a singleton or twin pregnancy ( = 0.993), on the dependent of luteolysis or luteostasis. The median IOI between individual mares varied significantly ( < 0.05) but was not correlated to the timing of MRP. The timing of MRP varied between the mares but was repeatable in each individual. The factors and mechanisms underlying the individuality in the timing of MRP were not determined and warrant further study.
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Publication Date: 2023-05-22 PubMed ID: 37238148PubMed Central: PMC10215440DOI: 10.3390/ani13101718Google Scholar: Lookup
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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 study investigates whether the timing of a mare’s recognition of pregnancy is specific to each individual. It does this by tracking when a mare fails to return to estrus after its embryos are reduced at different points during their pregnancies.

Study Setup

The researchers conducted this study on 10 selected mares, within which single pregnancies (150 in total) and synchronous twin pregnancies (9 in total) were reduced at specified time points within 10, 11, 12, 13, or 14 days of pregnancy. They executed between 5 and 29 reductions per mare.

  • The vesicle diameter of the embryos was recorded in 106 out of 150 singleton pregnancies before reductions occurred.
  • The Interovulatory interval (IOI), essentially the time between ovulations, was recorded 78 times in seven out of the ten mares. This included both pregnant and non-pregnant cycles.

Findings

The results showed that the earliest post-ovulation timing at which embryo reduction resulted in luteostasis (the failure to return to estrus) in an individual was at 252 hours, or mid-Day 10.

  • There were variations in consistent luteostasis following embryo reduction between individual mares, ranging from 272 to 344 hours.
  • Binary logistic regression analysis showed an effect of the post-ovulation interval at which embryo reduction happened. It also showed that the individual mare had an impact on the timing.
  • The research found no significant relations between vesicle diameter at the time of embryo reduction, whether the pregnancy was singular or twin, and whether the mare experienced luteolysis or luteostasis.
  • There was a significant variation in the interovulatory interval among mares, but this did not relate to the maternal recognition of pregnancy timing.
  • The timing of maternal recognition of pregnancy varied between mares, but for each individual mare, it repeated reliably.

Implications

Although the researchers identified a variation in the timing of maternal recognition of pregnancy in individual mares, they were unable to determine the specific factors or mechanisms behind this. Therefore, further studies would add value to this area. This understanding could eventually contribute to more effective mare breeding and pregnancy monitoring.

Cite This Article

APA
(2023). The Timing of the Maternal Recognition of Pregnancy Is Specific to Individual Mares. Animals (Basel), 13(10), 1718. https://doi.org/10.3390/ani13101718

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 13
Issue: 10
PII: 1718

Researcher Affiliations

Conflict of Interest Statement

The authors declare no conflict of interest.

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