Blood ionized calcium concentrations in horses before and after the cross-country phase of three-day event competition.

The research looks into the changes in the blood ionized calcium concentrations in horses before, during, and after a three-day cross-country event, noting a substantial decrease in ionized calcium during the competition, and a non-significant increase in total calcium. These changes, along with changes in other blood components, were shown to have low biological significance due to their low correlation.

Research methodology

• The study involved 40 healthy horses that took part in a three-day event competition.
• Different blood parameters were recorded at three key stages: before the event (T1), at the finish line (T2), and 10 minutes after finishing the event (T3).
• The measurements included: Blood ionized calcium (Ca2+), pH levels, plasma lactate concentrations along with total protein, total calcium (CaT), albumin, and phosphorus concentrations in serum.

Research findings

• The average levels of blood ionized calcium was found to decrease significantly from the beginning of the event to the finish line.
• This decrease was accompanied by a non-significant increase in total calcium. The degree of calcium ionization also decreased significantly.
• There were observed significant increases in average albumin, total protein, phosphorus, and lactate concentrations and a significant decrease in mean pH levels at the finish line.
• Although calcium ionization and mean Ca2+ had increased 10 minutes after the finish, they were still significantly less than the resting values. Mean CaT was noted to decrease significantly at this time as compared to values at T1 and T2.
• Correlations between mean Ca2+ concentration and all other measured variables were low, indicating low biological significance of the observed changes.

Conclusions and Implications

• The research indicated that horses experience notable changes in blood composition during rigorous physical activities like a three-day event, with the most significant being a decrease in ionized calcium.
• These changes, despite being statistically significant, were found to have relatively low biological significance based on their correlation scores, meaning these changes may not have major biological effects on the horses, but further studies are needed to confirm these findings.