Insulin Resistance (IR) horses require diets low in non-structural carbohydrates. And while insulin resistance is not curable, it is manageable. A key component to managing the condition is diet—a critical factor being choosing hay low in non-structural carbohydrates (NSC ).
Carbohydrates In Hay
Forage analysis data collected by Equi-Analytical between 2004 – 2020 reports the average NSC in these types of hay:
- Legumes: 10.85% NSC ( 8.7% low – 12.9 % high)
- Grass: 12.5% NSC (7.6% low – 17.35% high)
- Oat Hay: 22.13% NSC (14.82% – 29.4% high)
Selecting Hay
Knowing that IR horses should consume hay with 10% or less in NSC, the Equi-Analytics data tells us that of the forage they analyzed :
- Oat hay is not a good option for IR horses.
- On average, legume and grass hay have comparable NSC levels, but some grasses will chart lower than the lowest recorded legume.
- Grass hay’s NSC content can vary by nearly 10%, while legume NSC deviation is more stable, at 4.2%.
Plant maturity, harvesting and curation, and the environment greatly influence NCS levels and nutritional value as a whole. These unknowns make every harvest unique, even when supplied by the same producer.
Legume vs Grass Hay
The variability between legume and grass hay is not well defined, making it challenging to create a blanket statement that one is preferable over the other. Selecting the appropriate hay means interpreting a hay analysis.
A hay analysis is inexpensive and is well worth the minimal effort. Definitively understanding what an IR horse is consuming is the first line of defense against chronic lameness and additional health challenges.
(Remember, this is not a one-and-done situation; every time a new load of hay arrives, send a sample for analysis.)
Working With Your Primary Care Veterinarian
Using the data from the forage analysis AND the nutritional information found on feed bag tags, have a meaningful conversation with your primary care veterinarian. Wellcare appointments are an excellent time for a dietary review.
Take Away Message
A first step in managing an IR horse is controlling NSC levels in the diet. Armed with the data, work with your primary care veterinarian to devise an appropriate dietary strategy to stem related health issues.