Last summer, Emily King’s eventer Dargun (Dre) had to be withdrawn from the young rider Europeans after tying up on arrival. Emily had been concerned about his wellbeing and has since switched him to full turnout — eating only grass and soaked hay — with dramatic improvement.
“Dre can’t seem to process hard food, no matter how low-starch/low-glucose it is,” explains Emily. “He couldn’t keep weight on, his coat was dull and generally he’d just be unhappy. He would also tie up a lot after the cross-country.
“He now lives out 24/7,” she adds. “The only feed we give him is a handful of grass nuts at a show when the other horses are being fed.”
Dargun is proof that not only is it possible to compete an advanced eventer from the field, but that in some cases it is preferable. So, as we head into autumn, which sort of horse might benefit from a wholesale change in routine? The off-season could be the ideal time to assess whether full turnout would work.
Horses for courses
Equine physiologist and biochemist Dr David Marlin says that horses suffering from poor gastro-intestinal or mental health can benefit from turnout.
“Restricted grazing is often a contributor to gastric ulceration and stereotypical behaviour, so keeping horses out can help,” he says. “It’s their natural environment. In the wild, they cover huge distances and are constantly moving and eating. When we put them in stables, it’s contrary to how they’ve evolved.”
Studies have shown that domesticated horses do not differ substantially from their wild counterparts, either physically or psychologically. Some researchers argue that domestication has not removed basic needs such as grooming, bonding and playing, yet some management conditions do not allow for this.
David cautions, however, that a small number of horses could actually become more stressed in the field. “Those that are low in the pecking order may be better off in a stable where they won’t be bullied,” he says.
Generally, turnout has positive effects on a horse’s respiratory system. Stables often have minimal airflow, poorer air quality and horses are more likely to inhale dust particles and mould spores. Most, but not all, respiratory conditions improve when horses are living outside.
“Many people associate respiratory disease, such as equine asthma, with stabling,” says David. “It has been recognised over the past 30 years that a form of equine asthma we used to refer to as SPAOPD [summer pasture-associated obstructive pulmonary disease] is worse in some horses when they are outside — particularly at certain times of the year, whether it’s due to grass or tree pollen, dust or mould.
“A clinical examination of 14 elite endurance horses who lived out 24/7 found that 12 had evidence of respiratory disease. Conversely, many others suffer more in the stable.”
Some producers like their youngstock to live out, to toughen up and “be horses”. Similarly, David points to South African endurance horses, who are turned away at between six and 12 months and are barely seen again until they are rising four.
“There’s a sense of survival of the fittest,” he says. “They learn to fend for themselves and develop physical toughness.”
But is this toughness merely a bonus — or a necessity? In a 2010 study, feral horses were found to walk around 17km a day. In comparison, a research paper on riding school horses found that they received on average just 41 minutes of exercise, six days a week.
“This is very far from what horses evolved to do,” David points out. “In the wild, they mostly walk around all day long, but a competition horse does most of his work in a short period in trot or canter.”
Scientists at Michigan State University have found that to maximise bone strength, bone needs to be exposed to large forces — typically by sprinting, which gives it the signal to add mineral. The slow training that many horses undergo, ostensibly to build bone strength, may actually be detrimental as it accustoms the bone to slow speeds and low loads. The scientists found this to be especially true when horses were stabled, which led to “rapid and dramatic mineral loss from the cannon bone” in young stabled horses.
The university’s study on Arabian horses — some stabled for 24 hours a day, some on pasture for 12 hours and others on pasture for 24 hours — found that those turned out for 12 hours or more had increased bone mineral content. They also found that turning a horse out was usually sufficient to prevent bone loss in the early stages of training, stating: “A single sprint of 50-80m, once a day, five days a week, can produce dramatic improvements in bone strength.” This was particularly pertinent to horses in high-impact disciplines such as racing, eventing and jumping.
Certain problems can be improved by turnout, such as tying-up, filled legs and arthritic and inflammatory conditions.
“It’s generally better to maintain movement, but you have to take it case by case, because the horse doesn’t know that he is supposed to be taking it easy and you cannot easily control how much he moves in the field,” says David.
H&H vet Karen Coumbe reports that the more precious or valuable a horse often means it is less likely to be given the opportunity to benefit from being outdoors.
“But decent turnout is almost always beneficial both for physical wellbeing and enabling horses to relax and stretch their limbs, so it is the best option for most,” she says.
The main disadvantage of keeping a top performer at grass, adds David, is maintaining his athletic physique.
“A grass gut does not suit a high-performance horse,” he says. “If weight is a problem, look at management systems that allow the horse to stay out without eating as much. One option is to turn him out on good pasture for part of the day, then onto poorer grazing or an arena for the rest of the time.
“A study published earlier this year on standard bred racehorses in Scandinavia found that they can perform off a high-forage diet, so it is possible,” continues David.
“Water intake is also tricky to monitor. Even if you can measure it, you can’t account for evaporation.
“Spotting something amiss is usually easier in the stable. Some interesting technological developments are now available, however, such as Orscana. This is worn on the horse’s rug and connects to a smartphone, helping owners know what’s going on when they’re not there and alerting them to sudden changes in behaviour.”
For many people, stabling is the most practical use of the land and time at their disposal. A racehorse trainer with 150 horses can’t realistically train them all from the field, for example.
“Generally, as the intensity of training goes up, in my experience it gets harder to manage a horse entirely from the field,” concludes David. “But maybe we just haven’t worked out how to make it practical. We still know very little about this area, as there are so many contributing factors — what a horse eats and how much he rests and moves in the field.It really depends on what suits individual horses and owners.”
Ref Horse & Hound; 14 September 2017