The study supports research carried out last year that suggested hay soaking in winter tap water may be an unreliable method.

The Laminitis Consortium comprises world-leading equine veterinary, nutrition and research experts interested in collaborating on the important topic of laminitis. It includes the authors of this work: Dr Annette Longland of Equine Livestock and Nutrition Services (ELNS), Dr Pat Harris of the WALTHAM® Equine Studies Group and  Clare Barfoot of SPILLERS® .

It is now well known that feeding forage containing high levels of water-soluble carbohydrates (WSC) may lead to laminitis. Many owners of laminitis-prone horses and ponies soak their hay in an attempt to reduce its WSC content, which ideally, it has been recommended, should be below 10% to make it safe to feed. However, using cold water can result in a high variability of leaching among different hays, rendering the method unreliable in terms of making hay safer for laminitics.

This work examined several different hay soaking regimens using four different types of hay. The hay was soaked at varying initial temperatures (8,16 or 49oC), over different  timescales (1, 3, or 16 hours) and using  a variety of soaking methods. The conclusion was that soaking hay in water at a temperature of around 16°C for a period of 16 hours resulted in the greatest and most consistent loss of WSC. However, even then the average loss was generally less than 50% of the original WSC. Some hays in the UK contain more than 200g of WSC per kg of hay, so as pointed out by Clare Barfoot:

“Despite this exciting new research soaking hay should always be seen as an additional safeguard when it comes to feeding laminitis-prone horses and ponies. It’s crucial to have your hay analysed before feeding it to an animal at high risk of laminitis and you should always choose hay with the lowest WSC content you can find. If in doubt use a forage replacer to ensure you know exactly what you are providing.”

The Laminitis Consortium is continuing its work in this area and hopes to be able to identify further practices that will be of greater benefit to the horse owner faced with hay of unknown WSC content.