Why is forage so essential for wellbeing?
Many of you will be familiar with the three Fs for horse wellbeing of forage, freedom and friends. I wanted to dedicate a blog article to delving into each of these in turn and this one is about forage.
As you may already know, my approach is based on considering health and wellbeing from the interlinked angles of physical or physiological, mental or cognitive, and emotional, all combined. I am fascinated by the inextricable nature of these components and usually it is more effective to consider them together rather than any one in isolation. Forage for wellbeing is an excellent example of how all of these are interlinked because it is so fundamental to the functioning of the horse.
I would like to make a distinction here in that horses need both the noun “forage” and the verb “to forage” for their all round wellbeing. The horse as a species has evolved to extract nutrition from relatively poor quality plant material. Horses do this via various specialisations of anatomy and physiology that combine to mean that their overall strategy is to eat a lot of plant material per day, so foraging (the verb) is what they spend the majority of their time doing.
Let’s take a look at these adaptations of structure and function and for each, why amount, type, variety and timing of forage availability for horses is therefore inextricably linked with their wellbeing.
Firstly, the digestive tract. This starts with the mouth, including the lips and incisor teeth, which sort and prehend fibrous plant material, and the cheek teeth, which grind it. Food then passes down the oesophagus to the stomach, where gastric acid starts the process of digestion. In horses, this acid is produced constantly, in contrast to species such as humans and dogs, who eat meals instead of trickle feeding, and who produce acid in response to those meals. After the stomach comes the small intestine, where further digestion occurs, then the large intestine and caecum or hindgut, which is where the most significant digestion occurs. The hindgut functions rather like a fermentation vat, with a huge and varied commensalism (helpful) microbial population that basically digests the fibrous plant material for the horse, takes some nutrition for themselves but provides the horse with the nutrients they need. This microbial population is fascinatingly and inextricably linked to many aspects of physiology, likely including immune and nervous system function and even influencing emotions. The extraction of nutrition from forage profoundly influences metabolism, and in temperate climates, the changing of the seasons signals changes to metabolism, these signals being received in large part via the gut.
Secondly, a locomotor system that is adapted for both many hours of steady movement in the act of foraging and bursts of speed to escape from predators. It is also adapted to allow the horse to lower and lift its long head (necessary for being able to see predators above grass stems) without too much muscular effort via an ingenious elastic ligament system. Thirdly, a social system of the herd and a home range in which the herd travels in the act of foraging, moving according to many influences including learned experiences, weather patterns and likely many other complex inputs. And fourthly, adaptations of the senses that allow horses to forage (the verb), communicate with their herd mates, and monitor for and detect predators and other threats. These include vision, touch, smell and hearing but also more subtle senses and probably ones that we are yet to become fully aware of.
So in terms of forage for wellbeing, physically the horse’s digestive system needs forage to wear the teeth and mobilise the jaw, to protect the stomach lining from the constant acid production and to exercise the propulsive muscles of the digestive tract. Forage is mostly fibre, which is the substrate for the microbial population of the hindgut. Type, variety, amount and timing of fibre input will all alter microbial dynamics and this has both local gut effects and more distant whole-body, metabolic and emotional effects. In the act of foraging, horses achieve movement, which is central to their whole wellbeing including physically exercising their locomotor system, affecting nervous system state and emotions, and cognitive processes. The act of seeking out, sorting and selecting forage is a decision-making or sometimes even problem-solving cognitive process. And foraging is self-soothing and is synonymous with the parasympathetic nervous system, in which the horse feels grounded, comfortable and able to learn. Usually if horses are foraging they are also achieving the other two Fs of freedom and being with friends.
Practical takeaways from this are:
As far as is possible, always provide 24/7 free choice forage. If you have an obese, insulin resistant (aka equine metabolic syndrome or EMS) or Cushingoid horse (aka pituitary pars intermedia dysfunction or PPID) you may have to put some safeguards in place but long term these safeguards actually shouldn’t involve any degree of forage restriction
Provide variety in forage offered to exercise the decision-making part of foraging (the verb)
Allow horses access to an area to roam far enough that they can exercise freely at all gaits, not just a stable or small pen, and with company they enjoy.
