Fructan

Recent research in Great Britain on grass founder is providing new strategies that might help prevent laminitis. Fran Jurga writes in the February edition of The Horse that the amount of fructan grass contains seems to be an important risk factor.

Temperate grasses are high in water soluble carbohydrate (WSC), which is made up of varying levels of sucrose, fructose, glucose, and fructans, which are chains of fructose molecules linked together. When stresses such as low temperatures and disease slow the rate of grass growth, fructan levels can rise. Close grazing also can play a role.

Fructan is considered beneficial to the digestive health of pigs and humans, but the situation is different with horses. A diet extremely high in fructan might lead to changes in the hind gut, such as the proliferation of some species of bacteria and microflora and the decimation of populations of other organisms. Researchers speculate this might be the cause of grass-induced laminitis.

It is an easy leap from news of these findings that mixtures of grass seed for pastures, especially mixed with species that might be stress-resistant or biologically engineered, could control fructan levels and make it possible to decrease the risk of laminitis.

Varieties of grass low in WSC, particularly varieties of ryegrass from Australia and New Zealand, might be mixed one day soon to make pastures so that foundered horses, which often are relegated to stalls and sandy pens, can enjoy turnout with their healthy buddies. Also, a testing protocol could be developed so that horse owners could measure the fructan level in grass before turning a horse out to graze. However, such testing may only provide a limited solution, because individual horses might have widely varying tolerances for fructan.

Dr. Annette Longland and Dr. Andrew Cairns, who are based at the Institute of Grassland and Environmental Research in Wales, believe that owners of horses at risk for laminitis should not turn out the animals in pastures during the growing season. The researchers recommended grasses low in WSC content for hay, particularly if the plants are mown after flowering. They also recommended alfalfa, which is a low-WSC legume.