Long-term effects of endurance training on total tract apparent digestibility, total mean retention time and faecal microbial ecosystem in competing Arabian horses.

The research investigates the impact of long-term endurance training on the digestion abilities and gut bacterial ecosystem in Arabian endurance horses. It found that after conditioning periods, these horses displayed increased digestibility which may provide them with more energy from forage degradation.

Study Overview

In this research, the scientists were interested in uncovering the effects of long-term endurance training on horses. They specifically focused on studying the digestibility of food, i.e., the horse’s ability to break down and absorb nutrients from the food, and the changes in the faecal microbial ecosystem.

The subjects of this study were purebred Arabian horses which were observed over two years for two longitudinal experiments. The training periods of these horses were incremented according to endurance racing levels: 60, 90 and 120 km. Diet composition and intake remained similar during all five measurement periods.

Findings

The study discovered that:

• During the first year, there was an increase in the digestibility of Dry Matter (DM), Organic Matter (OM) and Neutral Detergent Fibre (NDF) after a training period of 10 weeks, which corresponds to the 90 km level.
• In the second year, the digestibility of Neutral Detergent Fibre (NDFd) and the difference between NDF and Acid Detergent Fibre ((NDF-ADF)d) showed a tendency towards an increase after 17 weeks of conditioning required for the 120 km level.
• However, the changes in digestibility were not consistently linked with longer overall mean retention time (MRT), which indicates how long the nutrients stay in the horse’s system, nor an increase in the microbial fibrolytic activity (activities of microbes that break down fibre in the gut).

Future Implications

The research highlights that endurance conditioning can increase digestibility in Arabian horses, which could provide them with more energy from forage degradation. The authors noted the need for additional experiments to fully understand the mechanisms behind this observation, to explain any contradictory results, and to investigate more about the techniques used in conducting this study.