Restricted Equine Diets and Wood Shaving Consumption

Obesity among equines seems to be a ubiquitous problem that leaves many owners seeking a weight loss program for their horse or pony. When it comes to devising a weight loss program, some caretakers turn to restricting the animal's caloric intake; however, one research team found that it's important to consider all possible materials that might be deemed as 'food' by a hungry horse, including stall bedding.

Wood shavings are a common form of stall bedding because they're typically seen as inedible, but a team of researchers from the University of Liverpool School of Veterinary Science, in collaboration with scientists at WALTHAM, in the U.K., noted recently that horses placed under dietary restriction might turn to consuming these shavings.

"This was a finding that came to light from a larger study which was designed to investigate restricted nutritional protocols for the corrective management of obesity in horses," explained Caroline McGregor-Argo, BVSc, BSc, PhD, Dipl. ECAR, MRCVS, an author on the study.

The researchers studied 12 mature, healthy horses or ponies with a body condition score (BCS) of 7 (out of a possible 9) or greater for 16 weeks. Animals were housed full-time in individual stalls with wood shavings with the exception of 30 minutes of turnout (with anti-grazing muzzles) each day.

Study horses were restricted to eating 1.25% of their bodyweight of a forage-based diet in order to achieve weight loss, but in measuring the 'apparent digestibility' of each horse's diet, it became clear to the researchers that nearly half the horses were excreting a greater amount than they were being fed.

"The only biologically plausible explanation was that at least half of the animals were supplementing dietary provision from an alternative, 'non-feed' source," the team said.

The team explained that the horse's natural feeding behavior includes grazing for 40-60% of the day. When food intake and time spent eating is reduced, a horse might seek alternative sources of 'food' to fulfill this natural feeding behavior; in this case, the researchers determined that the alternative food source was the wood shavings the animals were bedded on.

Although all animals remained healthy throughout the course of the study, "the potential is there for wood shavings to cause problems," relayed McGregor-Argo .

The team recommends careful observation of horses on dietary restriction for weight loss, and "where wood shaving ingestion is recognized or indicated by fecal bulking, the use of rubber matting alone should be considered."

The study, "Voluntary ingestion of wood shavings by obese horses under dietary restriction," was published in the British Journal of Nutrition in October 2011. The abstract is available online.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.