The effect of mixing and changing the order of feeding oats and chopped alfalfa to horses on: glycaemic and insulinaemic responses, and breath hydrogen and methane production.

This research examines how the order and manner in which we feed horses oats and chopped alfalfa affect the horse’s blood sugar, insulin response, and production of hydrogen and methane in their breath. The study found the highest blood sugar and insulin responses when horses were fed oats and alfalfa separately, while consumption of oats alone produced the most hydrogen.

Research Method

• The study involved feeding horses with two types of feeds – chopped alfalfa, which served as a source of dietary fibre and unprocessed oats as a source of starch.
• The feed intake for horses was controlled for each type of feed. Chopped alfalfa intake was set at a crude fibre intake of 0.5g/kg body weight per meal, while the oats intake was set at a starch intake of 2g/kg body weight per meal.
• The feeds were administered in three ways:
  • Alfalfa followed by oats (A/O)
  • Oats followed by alfalfa (O/A)
  • A mix of alfalfa and oats (A+O)
• The control group was given only oats.
• Blood and breath samples were collected after the meal at the end of an 11.5-hour overnight fast following a 10-day acclimatization period.

Findings

• The study found the highest glycaemic (blood glucose) and insulinaemic (insulin) responses when horses were fed with A/O and O/A diet sequences.
• Most hydrogen was produced when horses consumed oats alone.
• While adding alfalfa to oats prolonged pre-caecal (before reaching the first part of the large intestine) digestion of starch, there was no evidence that this process affected the pre-caecal starch digestibility.

These findings suggest the order of feeding and the type of feed can significantly influence the metabolic response in horses. More understanding of these processes can support better feeding strategies for horses, improving their health and performance.