At a full gallop a horse will inhale around 1,800 litres (that’s around 6 bathtubs full) of air per minute, while up to 300 litres of blood are pumped throughout the body and right down to the tiniest of blood vessels in the lungs to remove oxygen and deliver waste carbon dioxide. Any restriction or inflammation of the airways will reduce the efficiency of this molecular exchange and therefore impact the supply of oxygen to muscles, inhibiting their normal function.
After injuries affecting the musco-skeletal system, respiratory disorders are the most common issue that limits performance in sports horses, so it is well worth paying attention to how we can improve respiratory function. Interestingly, despite its critical importance to equine health and performance, the respiratory system doesn’t get larger or more efficient with training and exercise in the same way muscles do. The only way to ensure optimum respiratory performance is to carefully manage the environment a horse is kept in to manage the risk of infection and irritation to its airways. Low level respiratory disease may have no outward sign at all, so prevention is definitely better than cure.
Stabling horses and feeding them forage are both very common factors in modern stable management. In most countries it isn’t possible for equines being trained for athletic performance to be kept at grass all year round so they are stabled and therefore subject to the dust, mould and spores in bedding, hay and haylage. Most professional yards have ventilation in place, use wood shavings in place of dusty straw and may soak or steam hay to try to wash away any dust contained in it. Sadly, simply soaking hay actually increases the levels of bacteria and spores in it, so this can be counter-productive.
Research carried out by Dauvillier and Westergren concluded that steaming hay lowered the levels of mould, fungal spores and bacteria, meaning it can be fed to horses without risking the development of respiratory irritation or infection. In fact, steaming hay with a Haygain steamer improves the hygienic quality of hay and reduces the risk of a horse developing an inflammatory airway disease by 63%. It can also extend the shelf-life of haylage by up to four days so is perfect for taking to competitions, meaning there’s no need to compromise on respiratory health when travelling.
The Haygain steamer enables yards to focus on schooling and fitness levels in performance horses, safe in the knowledge that they are using the most effective and reliable method to ensure they are only feeding forage that is keeping respiratory systems healthy.
With thanks to Dr David Marlin and Haygain for their knowledge and expertise.