Could Molinia caerulea be an alternative forage feed for horses?

Molinia caerulea (Molinia) is a native plant species that dominates large tracts of the UK uplands, with detrimental impacts on floristic diversity and related habitat value. Harvesting Molinia supports biodiversity restoration and conservation, yet there is little incentive for farmers to manage this increasingly dominant species. Our aim was to evaluate Molinia's potential as an alternative forage for feeding horses based on published nutrient analysis data. Though research is limited, chemical analysis suggests Molinia is typically comprised of high energy, low water-soluble carbohydrate (WSC), but is high in fibre, resulting in poor digestibility and low metabolisable energy provision in cattle. However, low WSC, high fibre diets are favoured for feeding domestic horses where inappropriate nutrition is typically associated with obesity and metabolic disorders. Ryegrass hay, commonly fed to horses, typically has a WSC concentration of around 180 g/kg DM, which exceeds recommended thresholds and is far greater than reported for Molinia (50–70 g/kg DM). We recommend further research to understand how this plant is degraded in the equine hindgut, using in vitro gas simulation and production experiments, to explore how Molinia is degraded in the hindgut and the extent to which it could contribute to or affect gastrointestinal health, prior to in vivo studies. Were the potential of Molinia as an equine feed proven, three-fold benefits would result: a new source of low WSC forage suitable for domestic horses susceptible to weight-related metabolic disorders; a new income stream for farmers in marginal areas; improved upland grassland biodiversity.