foran equine advertorial
Gut instinct Written by: Nichola Reynolds, MSc. Nutritionist at Foran Equine and Connolly’s Red Mills
A
NYONE WITH A vested interest in optimising the equine athlete’s health, welfare, and performance will be aware of the important role that the hindgut plays in all these things, and how its functioning can impact everything from behaviour and performance, right through to immune health. Over recent years advancing research techniques have allowed a better understanding of how different management regimes can affect the hindgut and its resident microbial population (the microbiome). Owners and trainers have seen first-hand how specific improvements to management regimes can improve hindgut health and in turn have a direct impact on condition and performance.
What is the microbiome?
The equine microbiome is a population of micro-organisms that colonise the hindgut; it is made up of bacteria, fungi, and protozoa. This population of microbes has many functions, but primarily they are there to ferment (digest) fibre through fermentation. A healthy, balanced microbiome is essential for efficient fibre digestion and utilisation. Over recent years we have gained a better understanding of how critical the microbiome is to a healthy immune system, balanced
56
The latest research into the role of the equine hindgut and its importance to the horse
temperament, and overall wellbeing. Research in the human field has already shown connections between our microbiome and its relationship with performance, recovery, long-term health, emotional well-being, and mental clarity. The healthy and balanced microbiome that we are striving for in our horses relies on a varied and plentiful supply of fibre from forages, including different grasses and conserved forages, such as hay or haylage. Horses naturally forage either in the wild or some domesticated settings. This natural foraging provides a vast array of plant material to satisfy this internal population of microbes and ensures that the fibrolytic, or fibre loving bacteria, remain the dominant microbe. This results in a robust microbiome, which is more capable of resisting certain disruptions, for instance those
caused by management changes and environmental stressors, more readily. For horses where their microbiome is less healthy and more unstable, certain management factors could potentially lead to a much more damaging disruption and thus increased risk of problems including hindgut acidosis.
What is hindgut acidosis?
Put simply hindgut acidosis occurs when the pH (see Box 1) in the hindgut is shifted down the scale to less than pH 6. This change in pH is usually due to a shift in the bacterial population in favour of more lactic acid producing bacteria as well as an increase in the production of Volatile Fatty Acids (VFAs). The change may occur suddenly and cause acute problems, or it may be more of a repeated insult causing a more chronic set of problems, such as:
The pH scale This measures how strongly acidic or alkaline a solution is. Pure water is neutral with a pH of 7. Acidic solutions have values less than 7, and the closer to 0, the more acidic it is. Alkaline solutions have values more than 7, and the closer to 14, the more alkaline it is.
www.internationalthoroughbred.net
• Decreased forage utilization • Changes to body condition (usually a loss of condition) • Changes to behaviour and demeanour • Intermittent discomfort • Inappetence • Colic • Decreased absorption of nutrients • Laminitis • Diarrhoea/colitis
How and why does it occur?
Firstly, it’s necessary to understand the function of the hindgut, which is made up of the caecum, large colon, small colon and rectum. It is the most important part of the equine digestive system as it is where fibre is gradually fermented by microbes. This process produces VFA’s, which permeate the lining of the caecum and colon, travelling in the bloodstream and eventually being utilised as an energy source for the horse. VFA’s are a major contributor to the horse’s daily energy demands, even in racehorses where traditionally we tend to rely more heavily on cereals to provide energy. The microbiome works best when their environment, including the pH, remains fairly constant. Certain factors associated with racehorse management increase the risk of the hindgut pH becoming too acidic (i.e. hindgut acidosis) these include: 1) Low forage intake. Adequate forage intake is essential
