As the world-wide equine population ages, a British based research group is continuing research into the health of older horses.
Work conducted by the Waltham Equine Studies Group, which underpins the science behind the Spillers horse feed brand, is helping to improve nutrition-related knowledge to enhance the health and quality of life of senior horses.
Waltham’s Professor Pat Harris said collaborative work is ongoing at the Universities of Minnesota, Michigan, Kentucky and Melbourne into the role of diet on tissue insulin resistance and the insulin response to an oral starch or sugar rich meal, as well as the gut microflora in the older horse. The Spillers team has also been working with colleagues at the universities of Aberystwyth, Surrey and Liverpool, studying the microflora of the older horse/pony and its response to dietary changes.
“Our collaborations bring together world-leading equine veterinary, nutrition and research experts interested in working on the important topic of the older horse,” Harris said.
“We are committed to continuing to undertake work that helps support the wellbeing, performance and longevity of senior horses.”
In conjunction with the University of Kentucky, Spillers has been looking at the relationship between nutrition and the chronic inflammation associated with aging and PPID; and with respect to PPID specifically, work at Michigan and the RVC in London has looked at the effect of diet and analytical method on ACTH concentrations respectively.
Harris outlined several key findings of the research so far, including that healthy older horses have increased insulin responses, compared to younger horses, in response to a starch-rich or starch and sugar-rich meal. This suggests that older horses, whether or not they have been diagnosed with insulin dysregulation, need an appropriate diet and management plan to help minimise the risks associated with insulin dysregulation such as laminitis.
In practical terms this means restricting the overall amount of starch and sugar in the diet especially for those horses/ponies that already have additional risk factors such as obesity, native breeding or PPID.
Waltham researchers also found that the horse’s ability to digest key nutrients does not appear to decrease with age, although some differences in the microflora in the gut may be present. This is now being studied further in the pony.
Diet can also influence adrenocorticotropic hormone (ACTH) concentrations, which are measured to test for PPID, as can the method of analysis of ACTH.
Waltham’s journey into the feeding and management of the senior horse started in earnest with a PhD programme with Nottingham Trent University in the early 2000s into age-related changes in taste and feeding behaviour in the stabled horse. Studies continued at Michigan University looking at the effect of age on digestive function followed by the effect of diet on glucose and insulin dynamics.