Prediction of foaling using mammary secretion constituents.

The research study aims to improve the prediction of foaling in Thoroughbred mares by examining the impact of certain mammary secretion constituents. However, the results pointed out that the use of prepartum equine mammary secretion electrolyte concentrations for such predictions might be unreliable due to large variations between different mares.

Objectives and Methods

• The researchers aim was to test the previously published models for predicting the time of foaling using data derived from prepartum mammary secretions of Thoroughbred mares. In addition, they sought to develop a new predictive model based on concentrations of mammary secretion constituents.
• To do this, they measured concentrations of sodium, potassium, calcium, citrate, and lactose in prepartum mammary secretions of 20 Thoroughbred mares in the 2 weeks leading up to the expected foaling date.
• They attempted to fit models to predict the time of foaling using three different approaches: based on absolute concentration, change in concentration, and percentage change in concentration of mammary secretion constituents regarding actual intervals to foaling.

Results

• The results showed that concentrations of potassium, calcium, citrate, and lactose increased as foaling approached while sodium concentration decreased. However, these concentrations varied significantly between different mares.
• The models for predicting time of foaling based on the percentage change in electrolyte concentrations were found to be less accurate than those based on absolute concentration or change in concentration.
• When they applied the data from this study to two previously published models, the statistical sensitivity, specificity, and positive and negative predictive values of both models were lower than those originally reported.

Conclusions

• The findings suggest that the use of prepartum equine mammary secretion electrolyte concentrations for predicting the time of foaling is unreliable due to the large variation in both the absolute concentrations and change in concentrations between different mares.
• The researchers concluded that models which combine the data on mammary secretion electrolytes with physical and behavioural factors might provide a more accurate prediction of foaling than those based solely on mammary secretions.