Measurements of heart scores and heart weights in horses of two different morphic body types.

The research article focuses on the relationship between heart score and heart size in two different horse body types, specifically draft and racing. The study found no significant variation between the two types but a marked difference was observed in heart weight as a percentage of body weight.

Method of Research

• Heart scores and weights of ten horses (five of each draft and racing type) were evaluated in this study. The heart score represents the arithmetic mean of the QRS durations of the three bipolar limb leads for 10 cycles.
• The horses were euthanized using a captive bolt gun, a method often used in larger livestock, to accurately obtain the heart data.
• The actual weights of the horses’ hearts were recorded using an electronic digital scale, ensuring precision in measurement.

Findings of the Research

• The linear regression equation showed a significant negative slope when assessing heart weight versus heart score in racing type horses. This suggests that as the heart score increased, the heart weight decreased within racing types.
• For draft type horses, the regression coefficients for heart weight versus heart score were not significantly different than zero. This implies there was no notable relationship between these two variables within the draft type horse group.
• Interestingly, there was no statistically significant difference found between the draft and racing types when comparing heart scores, indicating that this metric is consistent across body types.
• There were however, significant differences when comparing heart weight as a percentage of total body weight. The proportion of heart weight to total body weight was different between racing and draft types, although the study does not specify which group had a larger or smaller ratio.

Conclusion of the Research

• The statistical analysis indicates that within racing type horses, there is a noticeable negative correlation between heart weight and heart size; while for draft types, there is no significant relationship between the two parameters.
• Despite these variations within body types, no significant difference was found between the heart scores of the two types of horses, indicating heart scoring as a metric is consistent regardless of horse morphology.
• The study, however, revealed a marked difference in the proportion of heart weight to total body weight between these two types of horses, though further research might be needed to better understand the implications of this variation.