The Microbiome of Pasture-fed Horses

Rightfully so, there is a lot of attention placed on the equibiome and its effect on the horse and his health.

The following study done at Massey University reveals some interesting points to consider before getting a microbiome test which can only truly give you a snapshot of what is happening in the gut at the time of testing for that particular horse.

The majority of studies to date document the changes in the microbiota caused by relatively sudden changes in the diet, or the effects of high carb/starch feeds on the flora populations, but here is a study where the same horses were kept on the same paddock for a year with no supplementary feeding apart from haylage in the winter.

This study (ref below) was conducted by Massey University in New Zealand.

The microbiome of 7 horses was tested every 2 weeks for a year.

Results revealed that the composition of the microbiota changed as a normal adaptation to dietary and environmental changes. There was a noticeable change when haylage was added to the diet over winter.

“The results of the current study suggest that fluctuations in the horse fecal microbiota associated with weather and dietary (forage) variations is normal. “The fecal microbiota of the study horses was found to be in a continuous process of adaptation and change in association with alterations in grass, supplementary forage and ambient weather conditions.” “Both the current study and previous horse microbiota studies reported significant inter-horse variation in gut microbiota composition.”

One completely over-looked aspect is that the health and composition of flora populations is inseparable from the health of the environment that they occupy.

The gut flora are bathed in a ‘soup’ encased by the walls of the digestive tract. The state/health of the soup is of primary importance to the health of, and has a massive influence on the balance of the species that make up the gut flora.

It is futile to try to get the right balance of gut flora by adding pre and probiotics while their environment remains volatile and unsuitable.

Reference **Variation in faecal microbiota in a group of horses managed at pasture over a 12-month period Shebl E. Salem, 1,2 Thomas W. Maddox,3 Adam Berg,4 Philipp Antczak,5 Julian M. Ketley,4 Nicola J. Williams,6and Debra C. Archer 6,7

CHH Australia Vicky Hansen and her horse, Diego