Implementation of field cardio-respiratory measurements to assess energy expenditure in Arabian endurance horses.

The study aims to measure energy expenditure in Arabian endurance horses during exercise, using a device called K4b2. This mobile gas exchange device records various parameters of cardio-respiratory activity in the horses, which then allow the calculation of energy expenditure.

Research Methodology

• The researchers utilized the equine K4b2, a portable device designed to measure gas exchanges. Even though the device has been validated for use in horses, it had not previously been utilized specifically for Arabian endurance horses. The device was used to collect data on various parameters:
  • Heart rate (HR)
  • Oxygen uptake (VO2)
  • Carbon dioxide production (VCO2)
  • Respiratory frequency (RF)
  • Tidal volume (VT)
  • Minute expired volume (VE)
• Data was collected from five trained Arabian endurance horses both at rest and during a 20-minute submaximal incremental field exercise.
• The relationship between heart rate and oxygen uptake was determined for each horse. This data was used to calculate the energy expenditure (EE) for the training session.

Findings

• Out of five horses, four tolerated the K4b2 well.
• The variables measured at rest and during exercise were consistent with previously reported values for exercising horses. For instance, VO2 ranged from 4.8 ml/min/kg at rest to 54.1 ml/min/kg during a canter. Energy expenditure ranged between 82 J/min/kg to 1095 J/min/kg.
• The energy expenditure for the 20-minute training session was between 6258 J and 6332 J. The researchers found that the values from direct VO2 measurements and calculated from the individual HR-VO2 regression did not significantly differ.

Conclusion

• The study concluded that after a period of adaptation and some technical adjustments, the K4b2 could be effectively used to assess energy expenditure in Arabian endurance horses in a controlled environment.
• The research also suggested that estimating energy expenditure based on the relationship between individual VO2 and heart rate could be a viable alternative when direct VO2 measurements are not possible.