There are a few management and feeding practices that can help preserve the digestive tract and microbiome of the horse.
The top priority should be to feed a diet based on forage, grass and hay and to limit concentrates as much as possible. For example, research has found that a change from a forage-based diet to a concentrate-based diet induces a rise in the lactic acid producing organisms and changes the composition of the species.
It has also been found that horses on hay and grass diets have a higher level of diversity and stability of the microbiome than horses on concentrate feeds.
The other potential way to help the Microbiome is to feed a Probiotic which is a ‘direct fed’ organism. Specific organisms are fed to the horse and then go on to populate and colonise the gut where they can help to maintain and restore the populations in the gut.
Prebiotics can also help, hi fibre feeds such as beet pulp, maxi-soy and psyllium husks can be fed as a source of easily fermentable fibre which feeds the gut organisms.
Psyllium husk fibre can be fed on a daily basis after being fully hydrated (soaked) as a prebiotic. Use around 50g/day for the average 500kg horse.
The addition of the amino acid glutamine at worming time or during other gut stressor events can help.
The scientific literature has demonstrated that glutamine is one of the main beneficial amino acids. It plays an important role in gut microbiota and immunity and can help support the gut in times of stress and change, dose rates are around 20g/day for the average 500kg horse.
Avoiding abrupt changes in diet are also very important, the microbes need time to adapt and change according to the food source.
Make feed changes slowly over a 10-14 day period.
If you can, avoid intense and prolonged exercise in the heat, this can negatively alter the composition of gut organisms and lead to digestive upsets.
If you must exercise in the heat, take measures pre- and post-exercise to ensure the gut is supported.
Support the gut before and after deworming.
Worming drugs are anthelminthics, not antibiotics, and do not have a direct negative effect on the biome in the horse. However, its thought that the removal of intestinal parasites may itself have a negative effect because of the alterations in the gut environment when they are removed.
Feeding pre and probiotics at worming time is likely good insurance.
Water is one of the most important components of digestive function and is needed for the production of secretions, enzymes, absorption, fermentation and the smooth passage of food through the digestive tract.
Horses not on fresh pasture need extra water as hay is only 10% water whereas grass is over 70%.
Feeding adequate salt will help balance electrolytes and trigger the horse to drink.
Avoid unnecessary antibiotic use.
The effect of antibiotics reduces the bacterial richness and diversity of the Microbiome and its been shown that it can take the gut over a month to recover and that the negative effects can persist for much longer.
The take home message here is that the horses microbiome can be easily damaged by some feeding and management practices, some of these can be easily avoided, others not so much.
Manage your horse accordingly and provide extra gut support when needed.