Energy under-nutrition in the weanling filly foal. III. Effects on heart rate and subsequent voluntary food intake.

The research article discusses the effects of energy under-nutrition in young female horses, and how it impacts their heart rate and subsequent voluntary food intake.

Experiment Design

• The researchers conducted two separate experiments where they monitored food intake and heart rate in New Forest and Welsh filly (young female) foals.
• These filly foals were either maintained at a constant weight by restricting their energy intake or allowed to grow normally for 180 days (New Forest foals) or 147 days (Welsh foals).
• After these periods, voluntary food intake was recorded over a course of 107 days (New Forest ponies) where they were fed the same diet. In contrast, herbage dry matter intake was recorded for the Welsh foals over 42 days where they had free access to pastures.

Experiment Findings

• In the ponies maintained at a constant weight, a decrease was observed in food intake and heart rate, and these values stabilized at new low levels.
• For the Welsh ponies, it was observed that those who were maintained at constant body weight previously, consumed a significantly higher amount of herbage dry matter relative to their metabolic body size (W0.73) when compared to the ponies who were allowed to grow normally.

Implications of the Research

• The research provides insights into the physiological impact of undernourishment in horses and the effect of caloric restriction on heart rate and voluntary food intake.
• Furthermore, it underlines the significance of careful management of nutrition in younger horses, by highlighting the varied responses between cohorts, especially considering the filly foals who had been maintained at constant weight previously.