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

Abstract

SummaryReasons for performing study: In endurance horses, commonly fed 80% forage, energy is provided mainly by VFA produced in the hindgut during cell wall degradation, but cell wall digestibility has been reported to be impaired by exercise. Objectives: To assess the influence of a long-term endurance conditioning on cell wall digestion in horses. Methods: The total tract apparent digestibility of dry matter, organic matter and fibrous constituents, solid and liquid total mean retention time and the faecal microbial ecosystem of purebred Arabian horses were measured for 2 years in 2 longitudinal experiments. Measurements: Performed at the beginning of each year for control level and after conditioning periods corresponding to incremental endurance racing levels: 60, 90 (year 1) and 120 (year 2) km. During the 5 measurement periods, feed intake and diet composition were similar. Results: In year 1, digestibility of DM, OM and NDF was higher after 10 weeks of training (P = 0.008, P = 0.010 and P = 0.031, respectively), corresponding to the 90 km level, compared to the pretraining level. In year 2, NDFd and (NDF-ADF)d tended to be higher (P = 0.06 and P = 0.07, respectively) after the 17 weeks conditioning necessary to reach 120 km level, than before training. These variations were not systematically associated to a longer total MRT, neither to an increase in the microbial fibrolytic activity. Conclusions: Digestibility of DM, OM and NDF appeared to be higher after endurance conditioning. Such an increase could be beneficial for endurance horses as it would provide more energy from forage degradation. Additional experiments are needed to elucidate the mechanisms, understand some contradictory results and investigate methodological aspects.evj_188 387..392

Influence of work on nutrient utilisation in semicaptive Asian elephants (Elephas maximus)

“…Matthewman and Dijkman (1993) reported better mixing of digesta in working animals resulting in improvement in microbial profile and digestibility. Similar increase in digestibility of DM, OM and NDF was also reported in horses after endurance work (Goachet et al 2010).…”

The impact of dietary protein levels on nutrient digestibility and water and nitrogen balances in eventing horses1

“…In the present study increasing dietary protein levels had an impact on the digestibility coefficients of CP, NDF, and ADF and tended to have an impact on the digestibility coefficients of DM and OM for horses subjected to intense exercise. Goachet et al (2010) reported higher values for the DM digestibility coefficient, 67.7% and 69.2%, for intensely exercising horses with DMI of 1.7% of BW. According to Goachet et al, conditioning had an impact on digestibility, and this impact improved DM, OM, and NDF digestibility.…”

“…A linear increase in digestible protein was expected on the basis of the linear increase of CP intake and linearly increasing response of the CP digestibility coefficient. Anywise, all the positive digestible effects are beneficial for exercising horses, which need an efficient and highly digestible diet (Goachet et al, 2010).…”

“…Values of NDF digestibility higher than those observed in the present study were verified by Godoi et al (2009), who reported an NDF digestibility value of 48.8% in oil-added diets with 13% CP in horses undergoing moderate conditioning. Also, Goachet et al (2010) measured an average NDF digestibility value of 51.9% in conditioning horses fed diets with 11% CP.…”

Muscle physiology and nutrition in exercising horses

“…2010). A 2 year study of competing Arabian endurance horses found a tendency for improved feed digestibility after training suggesting an influence of long‐term endurance training on cell‐wall digestibility in horses (Goachet et al . 2010).…”