Effect of increased adiposity on insulin sensitivity and adipokine concentrations in different equine breeds adapted to cereal-rich or fat-rich meals.
Authors: Bamford N J, Potter S J, Baskerville C L, Harris P A, Bailey S R
Journal: Veterinary journal (London, England : 1997)
Summary
# Editorial Summary Dietary composition appears to drive insulin dysregulation in obese horses more significantly than excess weight alone, according to research by Bamford and colleagues examining 33 horses and ponies fed either cereal-based, fat-based or control diets over 20 weeks. Both supplemented groups achieved comparable obesity (200% of maintenance digestible energy intake by week 20), yet only the cereal-fed animals developed measurable insulin insensitivity—lower insulin sensitivity indices and elevated acute insulin responses to glucose—whilst the fat-fed group remained metabolically similar to controls despite matching weight gain. Breed differences emerged independently of diet: ponies and Andalusians demonstrated inherently lower insulin sensitivity than Standardbreds, a finding relevant for risk-stratifying laminitis-prone animals within populations. The cereal-fed group also showed significantly depressed adiponectin concentrations compared to controls, whereas fat-fed horses maintained normal levels, suggesting the glycaemic stress of high-carbohydrate feeding may suppress this protective adipokine regardless of obesity status. For practitioners advising on weight management or laminitis prevention, these findings highlight that feed type—not simply caloric restriction—warrants careful consideration, particularly for naturally insulin-dysregulated breeds, and support prioritising forage-based or fat-supplemented weight-loss protocols over grain-based approaches.
Read the full abstract on PubMed
Practical Takeaways
- •Feeding cereal-based concentrates poses greater insulin dysregulation risk than equivalent caloric fat-based feeds, even at the same body weight gain — consider fat-rich alternatives for at-risk horses and ponies
- •Ponies and Andalusians appear genetically predisposed to lower insulin sensitivity regardless of diet; these breeds warrant stricter caloric control and glycaemic load management
- •Weight gain alone does not necessarily cause insulin problems if achieved via high-fat diets; the type of calorie source matters more than total caloric load for metabolic health
Key Findings
- •Cereal-rich diets induced significantly lower insulin sensitivity (P<0.001) and higher acute insulin response compared to controls, independent of obesity induction
- •Fat-rich diets induced equivalent obesity to cereal-rich diets but did not impair insulin sensitivity compared to controls
- •Ponies and Andalusian horses demonstrated lower insulin sensitivity than Standardbreds across all diet groups (P=0.001)
- •Adiponectin concentrations were significantly lower in the cereal-rich group (P=0.010) but similar between fat-rich and control groups, suggesting dietary glycaemic load rather than adiposity per se drives adipokine dysfunction