Effects of various diets on gastric tone in the proximal portion of the stomach of horses.

This research sought to understand how different types of food, specifically grain and hay, impact the tension in a horse’s stomach. The researchers found that both types of food cause a two-stage relaxation response in the stomach, with the response potentially being influenced by the size of the meal.

Objective and Methodology

• The primary aim of this research was to examine how the proximal portion (upper segment) of a horse’s stomach responds to the ingestion of different diets. The diets in focus were two types of grain and two types of hay.
• To carry out the experiment, the researchers used 6 adult horses. For each horse, they inserted a polyester bag through a gastric cannula into the stomach. This bag, possessing a volume of approximately 1,600 millitres, was used to measure changes in the stomach’s internal pressure, maintained at 2mm Hg using an electronic barostat.
• These horses were fed varying quantities (0.5 and 1.0 grams per kilogram of the horse’s weight) of both grain and hay. The researchers recorded changes in the volume of the bag before, during, and after the horses consumed these diets.
• Any changes in the bag’s volume allowed the researchers to infer changes to the tone of the gastric wall, as the volume of the bag was indirectly correlated to the gastric wall’s tone.”

Findings and Conclusions

• The researchers concluded that food intake, regardless of the type of food, triggered a significant two-phase increase in volume. The first stage of this increase happened during the active consumption of food, and was followed by a second, longer-lasting post-meal phase.
• It was further noted that the ingestion-related phase of the response to a diet of 1g of hay per kg of body weight was significantly higher than that of the other diets. This suggests that the type and amount of food can influence the gastric tone, with larger meals possibly leading to a greater initial relaxation phase.
• The study concludes that the consumption of a solid meal stimulates a biphasic relaxation response in the proximal portion of a horse’s stomach, supporting the notion that gastric tone is significantly impacted by the type of food ingested and the meal’s size. As such, this has implications for effective equine diet management.