Intestinal health and welfare of horses: can spent grain be developed into a feed supplement that maintains and improves the intestinal health of hors

Hevosten suolistoterveys ja hyvinvointi: voidaanko tuoremäskistä kehittää hevosten suolistoterveyttä ylläpitävä ja parantava tuote?

The number of horses with Inflammatory Bowel Disease (IBD) has increased in recent years. Spent grain has been used at horse clinics as a supporting treatment for horses with intestinal disorders and preliminary results have been promising. The aim of this project is to develop a domestic and commercial feed supplement by using spent grain (the main by-product of the brewing process) to maintain and improve the intestinal health of horses. The purpose of the project is to improve the profitability of primary producers and to increase plant protein self-sufficiency. The project promotes a circular economy and sustainable development becouse brewing waste can be used more effectively and less spent grain will end up to a landfill. On the whole, the project will improve the treatment of IBD horses and increase their welfare.

The project investigated the use of brewer’s spent grain (BSG) as a concentrate source for horses and as a possible prebiotic supplement. It involved both trials of different drying meth-ods of BSG, as well as feeding trials.
The hygienic level of dried BSG was not acceptable with none of the drying methods used, therefore other economical methods still need to be searched.
There were four different feeding trials of BSG: the first two were preliminary studies with adult horses; those concentrated on following the health of the horses and changes in the fecal consistency and pH during the feeding period. The latter studies were conducted during two consecutive years with yearling horses living in a loose-housing system. The third trial was to evaluate changes in fecal microbiome, when horses were fed BSG for two weeks. The fourth trial was to evaluate the microbiota changes when horses received anthelmintic medications while they were fed BSG.
The first two feeding trials showed no negative side effects in horses. In the third study the feeding of BSG changed the fecal microbiome of the yearlings very little; the gender and oat ratio explained more of the variation than BSG. The BSG supplementation during the last study changed the microbiome mildly and seemed to reduce the changes of anthelmintic medication. Even the anthelmintic did not greatly affect the microbiome.
Based on the trials it can be concluded that feeding BSG to horses is a safe practice. The project could not find any specific prebiotic benefit, but one must also remember that the knowledge of equine specific prebiotics is still vague.