How the loss of biodiversity in the horse's environment can/does affect/help cause the onset of EMS/obesity and laminitis.
According to the BHS, around 50% of the UK's horses are obese, with this figure approaching 70% for some native pony breeds. For many horse owners, keeping our "good-doers" trim and free from laminitis or EMS is an uphill struggle. This article briefly outlines the issues around equine obesity and the links to EMS in horses and chronic laminitis in horses. We then provide further detail specifically on how loss of biodiversity in our fields may be linked to these conditions.
Equine Obesity, EMS and Chronic Laminitis in Horses
Equine obesity can cause a plethora of issues, including Equine Metabolic Syndrome (EMS). EMS can in turn make a horse more prone to laminitis. Together, these conditions can spiral out of control and become increasingly difficult for even the most diligent owner to manage. But how can these serious conditions be linked to a loss of biodiversity?
Loss of Biodiversity & The Effects of Modern Agricultural Methods
There has been a continuous, rapid, and ongoing reduction in the biological diversity of plants and the ecosystems they support (i.e. soil, bacteria, animal health). The loss is so great it is causing global political and scientific concern.
The loss of biodiversity is especially rapid in those areas of land that have been exposed to the highest levels of agricultural intensification, so much so that reversing the process is thought to be impossible in some areas as the damage or loss has been so great. The fields in which many domestic horses are kept may have previously been used to grow crops or graze livestock, or they may have been grazed by horses for several years. These fields tend to have a lower level of biodiversity due to the use of pesticides, grazing of a single species or the repeated cultivation of a single crop.
This stands in stark contrast to the highly biodiverse moorlands, forests and bogs from where many British native ponies originate. The fields we graze our horses in are often designed for fattening cattle, and not for laminitic ponies!
How Do Modern Pastures Compare to Wild Habitats?
Most horses prone to EMS have originated from an environment of extremely high diversity, such as moorlands, heathland uplands, forests, and bogs. These lands span hundreds and thousands of hectares, the size of which encourages and supports the growth of many different types of plants that smaller cultivated areas (i.e. fields) cannot sustain.
Plants in these areas have evolved over centuries to suit the climate, complement and support each other against disease, as well as providing important ecosystem services (clean water and carbon sequestration). In contrast, the plants in the improved pastures, (covering 61% of the UK’s grasslands) consist mostly of genetically improved modern grass species, bred to provide high glucose/carbs and increased production of meat and milk. Improved grasslands are not self-sustaining and need high levels of human intervention and agrichemicals to remain viable.
Causes of Equine Obesity and EMS in Native Ponies and "Good Doers"
We often assume or are taught that the moorland, upland, forests, and bogs provide a poor diet and that the horses able to thrive in this type of environment have learned to survive on poor-quality fibre. We attempt to mimic this diet by providing (often low-quality) chaff and low-sugar (soaked/steamed) hay, topped up with a vitamin and mineral balancer, with a minimum time spent interacting with pasture/grazing. For many ponies, this is often the only way they can survive.
Genetics play a part in the continuation of the ‘good doer’ prone to EMS/laminitis/obesity, even when the health/survival support system on offer from the ecosystems of its original environment has been removed. Although we see the genetic contribution to an inherited tendency for obesity/EMS, we seem largely unable to value or consider the multi-functioning metabolic pathways that work through the direct interaction of the horse within a biodiverse environment. Thereby, we are possibly missing many crucial underlying causes of modern metabolic/endocrine dysregulation.
The Link Between Biodiversity and Keeping Native Ponies Healthy
The wide range of plants within a naturally evolved plant community will be lower in sugar and carbs (not required by many native ponies) and rich in chemicals that interact directly to regulate metabolism through the equine gut/brain axis and the gut/endocrine axis.
Simply put, biodiversity is the sole reason the inhabitants of these environments (horses and other animals) can and do survive. This interaction between the phytochemicals, the host (horse) microbial community and the signaling system (endocrine) controls all the aspects of metabolism, thereby ensuring survival.
The Role of Bioactive Peptides
We have long been aware of the existence, benefits, and interactions of the thousands of plant chemicals such as tannins, saponins and triterpenes.
However, a more recent discovery has the existence of bioactive peptides, hidden within the parent protein and only released by fermentation in the hind gut by the gut bacteria. As the horse relies heavily on hind gut fermentation and has a large holding vat solely for this purpose, it may be logical to assume an equal reliance on the nutrients/chemicals/metabolites provided by this process.
As though to prove a point, once released through the fermentation process, a large percentage of bioactive peptides directly control satiety, weight gain, and endocrine (insulin regulation) function through the gut-brain and gut-endocrine axes.
Bioactive peptides are not found in highly processed food or improved grass monoculture grasslands.
The Link to Diversity in the Microbiome
Some risk factors for the development of EMS, obesity and laminitis are genetically inherited, but a component of the antidote can’t be inherited and must be provided by the diet. If you want the horse to have a good metabolism, he requires a diet high in bioactive peptides and a hind gut microbial community able to release them from the parent protein.
Many horses have a microbial community with very few microbes able to cause the release of bioactive peptides, but a high percentage of microbes that can digest sugar and carbs (causing acidosis). Altering the microbial population away from acidosis is not only possible, it is highly recommended!