Comparison of pH and refractometry index with calcium concentrations in preparturient mammary gland secretions of mares.

The research conducted sought to assess the effectiveness of pH and refractometry, against measuring calcium carbonate concentration in preparturient mammary gland secretions to predict parturition in mares. The results indicated that testing pH was equally effective in predicting when mares were ready to give birth as the traditional method of measuring calcium carbonate concentration.

Experimental Methodology

• The researchers conducted a study involving 27 pregnant Thoroughbred mares.
• Mammary gland secretion samples were collected once or twice daily during the 10-day period leading up to foaling until the birth occurred.
• These samples were evaluated for calcium carbonate concentration using a water hardness kit, pH with test strips, and refractometry index with a Brix refractometer.
• The sensitivity, specificity, and positive and negative predictive values of each test were calculated to evaluate their ability in forecasting parturition.

Results of the Study

• For calcium carbonate concentration determination, the Positive Predictive Value (PPV) within 72 hours and the Negative Predictive Value (NPV) within 24 hours were 93.8% and 98.3% respectively, with the standard value set at 400 μg/g.
• For the pH test, with the standard value set at 6.4, the PPV within 72 hours and the NPV within 24 hours were 97.9% and 99.4% respectively.
• For the Brix test, the PPV within 72 hours and the NPV within 24 hours were 73.2% and 96.5% respectively, with the standard value set to 20%.

Conclusion

• The results suggested that a pH test, with the standard value set at 6.4, was useful in managing preparturient mares by predicting when mares were not ready to give birth.
• This method was as effective as measuring calcium carbonate concentration using a water hardness kit, which is the traditional method usually employed.

The results of this research can potentially aid in the improved management of pregnant mares and the timely prediction of parturition, ensuring better preparedness for the birth process and potentially reducing any complications.