Equine energetics. I. Relationship between body weight and energy requirements in horses.

The research study focuses on the correlation between a horse’s body weight and its energy requirements, concluding that they are directly proportional.

Research Methodology

• The study was conducted using indirect calorimetry on four mature horses, differing in weight from 125 to 856 kg.
• Each horse was exposed to three different, identical diets to vary their intake levels.
• To identify the amounts of digestible and metabolizable energy needed for zero energy balance, regression equations were derived for energy balance against energy intake.

Research Findings and Conclusions

• The study inferred a linear relationship between the weight of horses and their maintenance requirements, i.e., as the weight of the horse increased, so did its energy requirements.
• In the studied range, comparing horses by weight was found to offer no advantage.
• An equation was established to calculate the digestible energy (DE) requirement for horses confined to metabolism stalls: DE (kcal/d) = 975 + 21.28 X W. Here, W represents the body weight of the horse in kg.
• A slightly different equation, DE (kcal/d) = 1,375 + 30.0 X W, including an activity factor, was suggested if following guidelines stipulated by the National Research Council.

Impact of the Study

• This study can help equine caretakers, vets, and horse owners establish a better feeding regimen for horses based on their body weight and thereby maintain a healthy energy balance.
• This research brings an objective, mathematical approach into the assessment of horses’ dietary needs, moving away from normative or weight-based comparisons. Instead, it encourages a better understanding of individual energy requirements based on body weight and activity factors.