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

Abstract

Results suggested that the pH test with the standard value set at a pH of 6.4 would be useful in the management of preparturient mares by predicting when mares are not ready to foal. This was accomplished with equal effectiveness of measuring calcium carbonate concentration with a water hardness kit.

Decreasing pH of mammary gland secretions is associated with parturition and is correlated with electrolyte concentrations in prefoaling mares

“…Korosue and others (2013) measured the pH twice daily in 28 mares, and these authors reported that a pH of 6.4 determined by a semiquantitative method presented a positive predictive value for foaling within 72 hours of 97.9 per cent and negative positive predictive value within 24 hours of 99.4 per cent. As most mares foal during the late evening or early morning (Bain and Howey 1975), we considered that determining pH only once daily during early evening would facilitate prefoaling management.…”

“…Therefore, we hypothesise that measuring of pH in the mammary gland secretions once a day early in the evening would enable us to predict foaling. Additionally, Korosue and others (2013) found associations between pH and CaCO 3 determined by a semiquantitative method. However, the correlations between pH of mammary gland secretion and its correspondent electrolytes (ie, (Ca 2+ ), (Na + ), (K + ) (Mg 2+ ) and (Cl − )) have not been reported.…”

“…Complex methods based upon changes in concentrations of multiple mammary gland electrolytes failed to predict foaling in one study (Brown-Douglas and others 2002), but was useful when a simple score system accounting for different mammary gland electrolytes was applied (Ousey and others 1984). A recent study by Japanese workers reported that a reduction in pH (determined by pH strip test) of mammary gland secretions occurred in periparturient mares, and that twice daily determination of pH could effectively predict parturition (Korosue and others 2013). At this time, the mechanisms leading to a reduction in the pH of prefoaling mammary secretion is not known, and twice daily sampling may be impractical for small farms with only one or few periparturient mares to be monitored.…”

Prepubic tendon rupture in the mare

“…In addition to monitoring electrolytes, it has been reported that a reduction in pH occurred in peri‐parturient mares, and that twice daily determination of pH could effectively predict parturition (Korosue et al . ). This is valuable information, as a single pH measurement undertaken each evening is simple, practical and cost effective.…”

Testing mammary gland secretions to help predict when a mare will foal

“…Recently, Korosue and others (2013) demonstrated that a pH strip test of mammary gland secretions can be useful in the management of preparturient mares by predicting when mares are not ready to foal (negative predictive value for foaling within 24 hours of 99.4 per cent, which is similar to calcium carbonate concentration testing). Negative predictive value was also accomplished with equal effectiveness in measuring calcium carbonate concentration with a water hardness kit.…”