What can go wrong in the hind gut?
For modern horses fed grain and legume-based feeds, it is important that starch and protein is digested in the upper tract and their components absorbed in the ileum, as flow-through of such materials to the hind gut can promote undesirable bacteria, causing various metabolic and gastric problems.
Fructan sugars in lush grasses have been shown to cause laminitis in horses and ponies due to its activity in the gut (Pollitt et al., 2003) when fed in excess. To create a correct hind gut microfloral population, several issues need to be considered – early nutrition at weaning, introduction of beneficial bacteria, pH and limiting exposure to pathogens.
Imbalances in the hind gut can occur if very young horses are exposed to pathogens, especially at birth and weaning. This can lead to a lifetime of problems, such as poor weight gain and reduced maintenance of body condition, behavioural issues and repeat attacks of sub-clinical diarrhoea. Gastric upsets, resulting in e.g. diarrhoea, are caused when toxins from pathogens attach to the gut wall, rendering the lining cells unable to take up water and minerals, especially in the colon.
Effective administration of technical feed ingredients into the hind gut requires delivery into the lower region and for the ingredient not to be damaged by stomach acid. Hence, many of these ingredients may be encapsulated or protected on a carrier, or in an inert form that is unaffected by acidic conditions.