Postprandial glucose, insulin, and glucagon-like peptide-1 responses of different equine breeds adapted to meals containing micronized maize.

This research paper assesses how different breeds of horse respond to meals containing micronized maize in terms of glucose, insulin, and a hormone called glucagon-like peptide-1 (GLP-1), which is involved in the body’s regulation of insulin and glucose. It identifies that certain breeds produce more insulin and GLP-1 after eating these meals and suggests that this could indicate a lower sensitivity to insulin or increased GLP-1 release.

Research Methodology

• The study selected horses from three different breeds: four Standardbred horses, four mixed-breed ponies, and four Andalusian cross horses, with each horse in a moderate BCS (Body Condition Score).
• The horses were fed twice daily at a fixed time with meals composed of micronized maize, soaked soybean hulls, and lucerne chaff.
• The quantity of maize given to the horses was gradually increased over a duration of 12 weeks, which was meant to accustom the horses to the diet.
• Following the acclimation, the researchers collected blood samples from each horse to measure the concentrations of glucose, insulin, and GLP-1 (a hormone important in the absorption and utilization of glucose after a meal).

Findings

• There was no significant difference in the glucose levels among the three breeds of horses.
• However, both ponies and Andalusian horses exhibited significantly higher insulin and GLP-1 levels when compared to Standardbred horses.
• A positive association was observed between the concentrations of insulin and GLP-1 over time.

Implications

• This study suggests that the higher insulin levels in ponies and Andalusian horses could be attributed to either a lower sensitivity to insulin or an increased GLP-1 release.
• The findings are significant as elevated insulin levels are a known risk factor for the development of laminitis, a painful and serious disease in domestic equids.
• This fosters the need for further research into the enteroinsular axis – the system enabling the release of hormones from the gut that promotes glucose absorption – as it may play a crucial role in understanding equine metabolic health.