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Equine veterinary journal2024; doi: 10.1111/evj.14070

Conductivity of mammary gland secretions is a sensitive and specific predictor of parturition in mares.

Abstract: Accurate prediction of parturition is paramount to ensuring monitoring of delivery and preventing complications. Assessing the pH and electrolytes of the mammary gland secretions (MGS) helps detect impending parturition. As conductivity is related to electrolyte concentrations and pH, it could be a useful alternative for predicting impending parturition; however, this hypothesis warrants a critical assessment. Objective: To assess the ability of conductivity, pH, and Brix in the MGS to predict parturition and to investigate their associations. Methods: Field study. Methods: The MGS of periparturient mares (n = 241) was assessed daily for conductivity, pH, and Brix index from 320d until parturition. Receiving operating curve cut-off values for conductivity (≤4.8 mS/cm), pH (≤6.4), and Brix index (>23.6%) were used to calculate sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for predicting parturition in ≤24 h. Results: Impending parturition was associated with a reduction in conductivity and pH (p < 0.05), and conductivity was strongly correlated with pH (r = 0.88) and Brix (r = -0.80) (p < 0.05). Sensitivity, specificity, PPV, and NPV for parturition in ≤24 h for conductivity (82%, 91%, 77%, and 92%, respectively), pH (79%, 84%, 81%, and 71%, respectively), and Brix (72%, 79%, 66%, and 83%, respectively) were determined separated and pairwise. Of interest, the sensitivity, specificity, PPV, and NPV, of combining conductivity and pH, were 80%, 95%, 90%, and 88%, respectively. Conductivity (≤4.8 mS/cm) presented the greatest odds ratio for predicting parturition in ≤24 h, and coupling it with pH (≤6.4 pH units) doubled its odds ratio (i.e., 25.4-62.3). Conclusions: Field study. Conclusions: The conductivity of MGS is a sensitive and specific method to predict parturition. This is the first large-scale study showing that a combination of conductivity and pH is useful for predicting parturition in mares. The methods employed can likely apply to other settings with similar results.
Publication Date: 2024-02-25 PubMed ID: 38403880DOI: 10.1111/evj.14070Google Scholar: Lookup
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Summary

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The study presents that the conductivity of mammary gland secretions (MGS) is a sensitive and accurate way of predicting childbirth in mares. Enhancing this procedure by using both conductivity and pH significantly improves its likelihood of success in prediction.

Objective and Methods of the Study

  • The study aimed to assess the predictive potential of MGS conductivity, pH, and Brix for parturition, and to further investigate their relationships.
  • The study was carried out in the field with the MGS of 241 mares nearing parturition, and daily assessments were conducted, starting from day 320 until childbirth.
  • The cut-off points utilized for conductivity were ≤4.8 mS/cm, ≤6.4 for pH, and >23.6% for Brix index, respectively. Using these benchmarks, the researchers calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for predicting parturition within the next 24 hours.

Results of the Study

  • The results highlighted that impending childbirth is linked to a decrease in both conductivity and pH.
  • A strong correlation was found between conductivity and pH (r = 0.88), and an inverse relationship was observed between conductivity and Brix (r = -0.80).
  • Separate and pairwise measurements for sensitivity, specificity, PPV, and NPV were taken for conductivity, pH, and Brix. Conductivity displayed the strongest results with 82%, 91%, 77%, and 92% respectively.
  • The combined use of conductivity and pH proved beneficial in enhancing sensitivity (80%), specificity (95%), PPV (90%), and NPV (88%).

Conclusions of the Study

  • The research concluded that MGS conductivity was a sensitive and accurate predictor of childbirth in mares. It was further noted that the odds ratios predicting parturition within 24 hours were greatest for conductivity at ≤4.8 mS/cm. However, when coupled with pH at ≤6.4, the odds ratio dobule from 25.4 to 62.3.
  • This was the first large-scale study proving that a combination of conductivity and pH can be useful for predicting parturition in mares.
  • The authors suggested that the methods used could most likely be applied in similar conditions with comparable outcomes.

Cite This Article

APA
Magalhaes HB, Colombo I, Spencer KM, Podico G, Canisso IF. (2024). Conductivity of mammary gland secretions is a sensitive and specific predictor of parturition in mares. Equine Vet J. https://doi.org/10.1111/evj.14070

Publication

ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English

Researcher Affiliations

Magalhaes, Humberto B
  • Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
Colombo, Ilaria
  • Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
Spencer, Kianna M
  • Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
Podico, Giorgia
  • Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
Canisso, Igor F
  • Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.

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