Daily exercising : necessary and beneficial

The distance covered daily decreases with the size of the field or paddock. In a 2500m2 paddock, a horse will travel just over 1km. In the newer type of installations such as « active stables » or  « paradise paddocks » horses have been known to travel up to 5km per day.

For stabled horses, the daily distance is much lower, as little as 200m ! The reasons given are frequently lack of available space, but owners and riders, who never turn their horse out, give other reasons : risk of injury, less accessibility to the horse, grooming time and less motivation to work the horse out. The stable is then considered as a controlled and protective environment.

But horses need daily exercise, which is beneficial both for their health and their behaviour. Exercising solely through work is not equivalent to the exercise from being turned out.

The main gait favored by horses living out is the walk, rarely the trot or gallop. When ridden horses will cover between 2,5 to 5km/ hour – 5,8 km/hour in a horse walker. During a work session, the distances covered are therefore smaller than those of horses living in natural conditions. Moreover, the intensity of the exercise is condensed over a far shorter period of time. These restrictive conditions appear drastic when the horse does not leave the stable. The benefits of turning a horse out are numerous, and are potentially higher when horses are turned out in groups, a group being at least two horses.

Effects on the horse’s health, right from a very young age

Musculoskeletal development 

It is more and more apparent that exercising during the juvenile phase of a horse’s development plays a crucial part in determining the structure and  biochemical composition of the tissues composing the musculoskeletal system (particularly renewal of collagen), and thus improves the biomechanical qualities.

A descriptive study was carried out in 21 stud farms in Normandy, on 378 foals of different breeds (selle français, trotting race horses and thoroughbreds) between the 8th month of gestation, up to the age of 6 months. This study brought to light risk factors linked to the appearance of development orthopaedic disorders, which affect a foals limbs and joints, such as osteochondritis dissecans (OCD). These diseases are due to multiple factors, of which genetics, growth, exercise and feeding practices. At the age of 6 months 47 % of the foals were affected, of which 37 % affected by OCD. The risk factors brought to light by the statistical analysis were as follows :

• The breed, with nearly 3 times more risk for selle français horses than thoroughbreds ;
• The height at the withers at the age of 6 months, and the rate of growth, the taller horses with a faster growth rate were more at risk ;
• And exercise, with 3 significant factors:
  • Frequency of turning out : foals turned out every day, or living outside have 2,8 times less risk than those not turned out every day ;
  • The size of the fields : foals brought up in fields of less than 2,5 acres at two weeks old, and less than 15 acres at 2 months old, have 3,6 times less risk of being affected than those living on larger areas ;
  • Changing groups during the first six months multiplies the risk factor by 2.

Therefore it would seem that exercise is vital for the development of the skeleton and bone quality, and increases resistance to injury. On the other hand, situations or events which favor significant moving around or modifications within the group can lead to injuries.

It has also been noted that weaned foals subsequently living stabled have a smaller canon bone diameter than those living out permanently or part-time (12 hrs a day), confirming the assumption of a beneficial effect of exercise on maintaining or increasing the mineral content of the bones.

Note : Gender and feeding practices do not present any particular risk, the above results probably correspond to similar feeding practices.

The musclar system

One of the risks linked to the absence of exercise is recurrent exertional rhabdomyolysis, also referred to as tying up, or myoglobinuria. This condition is linked to confined rest, with no reduction in the energy intake, followed by moderate or high intensity exercise. Clinical signs include stiffness and muscle pain, inability or difficulty to move, sweating, destruction of muscular fibers and possibly myoglobinuria. The latter is due to a pigment from the damaged muscle being passed in urine, myoglobine (a molecule which is close to haemoglobin responsible for the red colour of blood), which gives the urine a brown colour.

This affliction generally reported in horses subjected to periods of intense work, alternating with forced rest with no exercise, has recently been reported more particularly in race horses in training, after one or two days of rest.

The digestive system

Living in a stable, even for horses being exercised for 60 to 90 minutes a day, and not being fed any concentrated feed, increases the risk of impaction (= blocking up of the intestine leading to colic). This shows up as a decrease in the volume of droppings, a decrease in the proportion of water in the droppings, and a reduction of the motility of the intestines.

Effects on behaviour at all ages

 A stabled horse’s time schedule (Berthier, 2015) Horses living in stables have a different time schedule to those living in the wild, or in semi-natural conditions

According to ethologists, this is one step towards deterioration of the horse’s well-being. In fact, when comparing the main activities carried out by stabled horses versus Camargue horses living on extensive farms, the activities differ as follows :

• The main travelling and moving around activities (1 % of the time for a stabled horse, versus 57 to 73 % for a Camargue horse) ;
• Resting time (37 % versus 18 to 38 %) ;
• Feeding time ( 45 % versus 51 to 64%).

Other authors have compared the time schedule for horses stabled round the clock to that of horses turned out in a paddock at night, or permanently in paddocks of less than or more than 2,5 acres : the time devoted to being active increases progressively from 1,2 hours a day to 12 hours a day.

Being stabled therefore significantly restricts a horse’s activities.

Horse who are not turned out are more stressed, less confident, and do not use up sufficient energy.

Moreover horses turned out for at least 1 hour a day appear less defensive and understand more quickly the requests of their handlers when being worked in hand than horses who only leave the stable for work ; the latter showing increased reactivty, and less inclination for obedience.

In addition, the more the horse is kept in, the more difficult it becomes to turn him out without risk of injury. This is known as the rebound effect. This has been shown through numerous studies, where depriving a horse of exercise results in a behaviour of intensified movement, including bucking, rolling, associated with neighing and whinnying, which increase the risk of injury for both the horse and the handler.

Finally, the beneficial effects of turning a horse out are potentially increased when turned out in groups. This has been observed on colts and fillies during breaking in over a 28 day period. When kept stabled individually, the youngsters required more time for each step of breaking in, than those living in a field in groups. This was especially true for the in hand phases. They also demonstrated more inclination for defensive behaviour and bucking when worked in hand or being ridden , thus proving more dangerous.

Restricting a horse’s accomodation to the stable leads to the development of stereotypic behaviour.

Even though lack of space and/or exercise are apparently not the major cause for sterotypic behaviour, they do represent a risk factor when associated with social isolation. A study conducted on 1750 sport horses detected sterotypic behaviour in 32,5 % of dressage horse, 30,8 % of eventers, and 19,5 % of endurance horses. For dressage horses and eventers, the risk increases with the time spent in the stable.

The horses were then subjected to choice tests :

1) They preferred to go back to the stable rather than being exercised on a treadmill, either 4800m at a trot, or 4000m at a trot followed by 1000m of canter ;

2) They preferred being turned out alone in a paddock to being stabled ;

3) They preferred being turned out with other horses to being turned out alone.

In addition, when deprived of going out for 48 hours, they chose to stay out in the paddock for a longer period of time with the other horses, as if to compensate for being cooped up. It would therefore seem that the motivation to feed is the strongest, followed by that of being out with other horses.