Inulin addition initiates different responses in laminitic and non-laminitic prone horses
Take Home Message: The hindgut bacterial population of ponies differs between laminitic and non-laminitic animals and is affected by the addition of inulin to the diet.
The bacterial populations of ponies’ hindguts respond differently to the addition of inulin to the diet in both laminitic and non-laminitic prone animals. And a clearer understanding of these differences may, in time, allow scientists to design strategies to avoid the changes in bacterial population in the hindgut of the horse fed diets high in rapidly fermentable carbohydrate that result in laminitis.
That was the conclusion of a study, carried out by researchers in England, Wales and Australia, to investigate changes in the number of streptococci and lactobacilli in the faeces of normal and laminitis-prone ponies following fructan administration.
Laminitis in the horse is associated with the over consumption of rapidly fermentable carbohydrate, in the form of simple sugars, fructans and/or starch. The fermentation of excessive carbohydrate in the hind-gut can result in the production of lactic acid and other toxins which in turn may act as laminitis ‘trigger’ factors.
“While it is known that susceptibility to laminitis varies within the equine population, little is known about the factors governing this variation,” the University of Aberystwyth’s Jamie Newbold told delegates at the British Society of Animal Science’s annual conference.
“Our work has previously shown that the bacteria extracted from equine faeces clustered weakly into two groups, representing normal versus laminitis-prone ponies. And this suggests a difference in gut microflora between the two groups. So we decided to extend this observation using real time PCR.”
Five normal and six laminitis-prone, native-breed ponies were acclimated to a basal hay diet before being fed a diet of inulin (3 g/kg of bodyweight per day), hay and chopped dried grass. No clinical problems occurred.
Fresh faecal samples were collected at -4, -2 , +2 and +5 days after the diet change. DNA was extracted using a DNA stool mini kit. These samples were then analysed using real time PCR on an Opticon system.
“There was no clear effect of either inulin addition or susceptibility to laminitis on the numbers of lactobacilli that could be recovered from the faecal samples,” said Professor Newbold. “But there was a dramatic increase in streptococci numbers recovered from the faeces of laminitis-prone ponies, but not non-laminitis prone ponies, following the addition of inulin.”
Presented to the British Society of Animal Science Annual Meeting, 30 March -1 April 2009, Southport, UK.
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