In Vitro Gas Production from Batch Cultures of Stomach and Hindgut Digesta of Horses Adapted to a Prebiotic Dose of Fructooligosaccharides and Inulin.

The research paper explores how fructooligosaccharides (FOS) and inulin, present in the diet of horses, might affect the process of fermentation in the gut. The study finds that these substances, introduced in the equine diet via Jerusalem artichoke meal, can accelerate the process of gas production within the horses’ stomach, and impact its pH levels, potentially influencing the health of the stomach.

Study objectives and design

• The central aim of the study was to examine if the intake of FOS and inulin, as a part of the diet, could influence fermentation in the digesta cultures from horses. The paper wanted to compare these results between horses supplemented with FOS and inulin, and horses without this supplementation.
• To conduct the study, six horses were given Jerusalem artichoke meal (JAM), a rich source of FOS and inulin, while six horses were offered corncob meal grains (CMG) as a placebo. After 20 days, the horses were euthanized for further examination.
• The digesta samples (contents of the digestive system) were taken from the stomach, cecum (a part of the large intestine), ventral colon ascendens (VCA, another section of the large intestine), and colon transversum (CT) of the horses.

Observations and measurements

• Researchers incubated the digesta batch cultures they collected for a duration of 48 hours. They measured levels of gas production, pre- and post-incubation pH, and oxidation-reduction potential (ORP) in this period.
• They observed a change in the fermentation, which used the surplus of fructans in JAM-fed horses’ digesta. The process of gas production was notably faster in these horses’ stomach contents compared to the horses fed with CMG.
• Despite buffering, the pH levels lowered during the fermentation. The pH following the incubation was lower in JAM than CMG-adapted batch cultures.
• The initial ORP was lower with stomach batch cultures adapted to CMG than those adapted to JAM. However, with JAM-adapted batch cultures, the ORP increased two times from pre to post incubation.
• The researchers observed that the maximum gas production decreased gradually using cecum, VCA, or CT digesta, indicating that FOS and inulin from digesta might ferment in the stomach, which could limit their effects on hindgut fermentation.

Implications of the study

• The researchers concluded that the ingestion of FOS and inulin might significantly influence stomach health due to increased fermentation. This study suggests the dietary composition, particularly inclusion of specific prebiotics like FOS and inulin, could play a crucial role in equine stomach and gut health.