Considerations before integrating your horse into a new herd
By Gwendolyn Donohoe (BSA, MSc)
My topic for this week is something that most of us “humans owned by horses” will have to experience at least once in our lifetime - moving a horse to a new group environment. Maybe a new horse has successfully stolen your heart and requested to come home with you! Or, maybe your current horse has decided that they need a new facility to meet their goals! Whatever the case, it is important to be prepared and knowledgeable about what to expect when moving a horse to a new environment, particularly when they are in group turnout.
This post will discuss some of the known research on integrating new horses into established groups. This information can help you prepare for the challenges that come with moving to a new barn, keeping in mind there are many other things to consider when moving as well!
What is the most common practice?
Every barn seems to have their own opinion and method for integrating new horses into group turnout. Turnout directly with the group appears to be the common method used, however, some barns have very specific strategies for dealing with this challenge, such as keeping mares and gelding separate to help reduce aggressiveness towards horses, or specific quarantine and “meet-and-greet over the fence” approaches. A survey in Europe found that 60% of farms put new horses directly into the group, while the remaining 40% preferred to do an over the fence greeting first (Hartmann et al. 2012). What is the best practice?
After much research on the subject, I found a great scientific review article about horse behaviour in groups (the stuff on Google really wasn't all that helpful or insightful). The article reference is below for those of you who want to keep reading up more on the subject, along with a couple of other interesting references I found.
- Keeping horses in groups: A review, by Hartmann, Sondergaard and Keeling. 2012. Applied Animal Behavior Science. Volume 136, pages 77-87.
- Stress response of three-year-old horse mares to changes in husbandry system during initial equestrian training. Erber et al. 2013. Journal of Equine Veterinary Science. Volume 33, pages 1088-1094.
- Emotional response of young race horses to a transfer from a familiar to an unfamiliar environment. Janczarek and Kedzierski. 2011. Animal Science Paper and Reports Volume 29, pages 205-212.
Why group turnout?
Before we can understand how to help our horse adjust to a new herd environment, it’s important to understand why we keep horses in groups in the first place. Why not keep horses on individual turnout to avoid these stressful situations in the first place?
Horses are social creatures and under natural conditions live in family bands or bachelor groups. These organized hierarchies of horses help to reduce a horse’s stress response to changes and danger (Erber et al. 2013). Keeping horses in groups has been well documented as the most humane and natural way to keep horses and has been proven to reduce aggressiveness, improve social skills, improve musculoskeletal development in young horses, improve training success, and lower reactivity levels in school horses, compared to individual turnout (Hartmann et al. 2012).
The downfall is that introducing a new horse to an established group can result in aggressive behaviour between herd mates as horses try to maintain or seek a new place in the group, and this introduction behaviour is documented to last for about one to two weeks (Hartmann et al. 2012). The resulting bites, chance of injury and lost performance/use over this time period is the primary reason for human stress when introducing a new horse as well!
One of the primary reasons humans have developed individual turnout is to reduce this chance of injury to performance horses during new introductions. Other reasons for individual turnout include reducing chance of injury from play between horses, ease of feeding specific diets, increased resting times, and horses being easier to catch. However, it has been well documented that these perceived notions are in fact false, as studies have found no increased injuries, decreased performance or other concerns when comparing performance horses on individual turnout to those in groups (Hartmann et al. 2012). In fact, studies have documented increased stress levels in young horses kept individually following moving them from a group environment (Erber et al. 2013). Keep in mind that if moving a horse for a short period of time (i.e. for training), individual turnout might be well warranted, as the one to two weeks of group introduction stress might outweigh the benefits of moving the horse in the first place.
The Meet and Greet Approach
So, if we are not going to keep our horse on individual turnout, the stress of introductions to a new group is inevitable. One method barns use to reduce aggressive behaviour during this time is to first introduce horses over the fence. Studies have shown that in young horses, whose social abilities are still developing, meeting over the fence first and getting some initial information about a new horse can reduce stress and aggressiveness when the horse is eventually turned out in the group (Hartmann et al. 2012).
However, the same study did not find the same results with mature horses. In fact, studies have shown that mature horses do not seem to be able to adapt to new introductions and horses that experience more frequent introductions do not get more receptive to new horses over time. How they react to a new horse in the herd is dependent entirely on the personality of the horse. Determining what horses are not good at new introductions (i.e. are overly aggressive) and removing them to a pen or group that does not have frequent introductions could greatly reduce stress for the entire group, particularly the new horse.
If the meet and greet approach is used to introduce a new horse to a group, it is important to keep in mind that horses are more stressed and have increased stressful reactions to change when they are by-themselves. Therefore, it may be a good idea to have a “meet and greet horse”, that is known to be less aggressive with new introductions, that can be a buddy for new horses during these quarantine and isolation procedures.
The other method that was mentioned was keeping horses in same sex herds. Typically this is done to reduce sexually related behaviour by geldings towards mares. However keeping horses in same sex groups is not typical of what is seen in the wild, and it is suggested that, particularly for young horses, mixed age and sex groups are important for social and physical development. Research suggests no increased aggressive behaviour or negative impacts from keeping mixed sex groups compared to single sex groups (Hartmann et al. 2012). Aggressive sexual behaviour by a gelding towards a mare is typically the result of past sexual experience by the gelding, and it is recommended that in mixed herds, geldings that have past sexual experience (i.e., gelded late in life) be kept separately from mares to avoid risk of injury or overly aggressive behaviour. There is no research to date to determine whether aggressiveness when introducing a new horse is increased or decreased by same sex groups, however.
Herd sizes, densities and feeding regimes
One last thing to consider in group turnout management is competition for food and overcrowding in pens, which can result in increased aggressiveness and stress to horses, particularly when new horses are introduced. Research suggests available space to exhibit grazing/foraging behaviour and adequate quantity and spacing of feed is essential to less competitive behaviour in groups and improved integration of new horses into that group. There is no magic number as to the best number of horses in a group, but numbers should be dictated by available space and feeding practices (Hartmann et al. 2012). In the wild horses can live successfully in groups ranging from 2 to 35 horses. Horses that are in pen sizes that allow vegetative growth (i.e., not just black dirt) is a common sense way to determine if a pen is over-crowded, and access to grazing space in the summer is ideal to reduce stress and improve social interactions in groups.
One interesting study noted that while under stress from moving to a new environment, young race horses were found to be most stressed during activities that required emotional responses to humans. Grooming was the most stressful exercise, compared to measurements during training and resting, because it appeared to stimulate an emotional arousal in the young horses (Janczarek and Kedzierski 2011). Until a horse is settled, it may be less stressful (on the human and horse!) to reduce activities that invoke emotional responses in horses until they have become established in their new hierarchy.
Having the resting/normal vitals of your horse before moving can be a good practice as an owner, so that you and the new barn staff can monitor how your horse is doing during the transition period. Knowing when your horse’s vitals have returned to normal , in particular heart-rate which is the most commonly used indicator of stress, will let you know when it's time to start increasing training, grooming sessions and other routine activities with your partner and will also help barn staff know when your horse has finally settled into the new group.
One other thing to keep in mind, based on my experience so far, is that moving an outdoor board horse can be more stressful than moving an indoor board horse. Outdoor board horses don’t receive the routine and alone time that indoor board horses do, and barn staff cannot monitor water or hay intake and vitals as easily to ensure that they are staying healthy over the first couple days. It is therefore important that outdoor board horses be monitored more frequently during the transition time and offered feed and water if it appears they are in isolation or being kept away from the group for long periods of time. Weather and access to shelter for these new horses should also be taken into consideration, especially during the winter months.
Summary: What to consider before you move to a new barn with group turnout
There is really no one scientifically proven method for integrating new horses into a herd. Things to keep in mind that may help reduce stress for you and your horse during these transitions include:
- Meeting over the fence may be something that a barn will try to reduce initial aggressive behaviour, however, it has not been proven scientifically. Also, such practices may be essential in the case of quarantine procedures. A "meet and greet horse" may be a good way to reduce stress for a new horse during this time so they are not in isolation
- Feeding practices and herd density are important points to consider when moving to a new barn, as this could dictate the degree of aggressive behaviour from the group every time a new horse is introduced to the herd
- If mixed sex herds are present, it is important to inquire as to the past sexual experiences of geldings
- Overly competitive horses and horses that do not do well with new introductions should be kept separately where they are not experiencing frequent introductions to new horses
- Special considerations for integrating outdoor board horses should be given, including extra monitoring and watching for isolation from food, water and shelter
- Have your horse's normal vitals before you move (heart-rate, temperature, etc.)
Always ask your vet!
Vets are always good resources and partners in horses health, and it is important to keep in touch with them for advice and feedback when moving a horse or looking for a new barn!