Research has linked cribbing to lower gastric pH in adult horses and gastric ulceration in foals. To address this concern, various supplements have been developed to neutralize acid and promote normal stomach activity in horses.
A randomised crossover study conducted by researchers from the University of Florida and the University of Costa Rica investigated the impact of a gastrointestinal support supplement on both cribbing and non-cribbing horses.
A full report of the work conducted by Ana M. Arias-Esquivel and colleagues at the. Institute of Food and Agricultural Sciences (IFAS) Equine Sciences Center in Ocala, Florida, is published in the Journal of Equine Veterinary Science.
The study, involved eight adult horses, with four showing cribbing behaviour matched with four non-cribbing horses of similar age and sex. These horses grazed on a Bermuda grass paddock during the day and were housed in individual box stalls overnight with visibility to other horses.
The researchers randomly assigned the horses to receive either the gut health supplement or a placebo of alfalfa / timothy hay pellets. Both the supplement and placebo were mixed with a concentrate feed and fed to the horses twice daily. The study spanned a 74-day period, including 14 days of acclimation, two 21-day feeding trials, and a 14-day washout period.
Throughout the study, various assessments such as blood samples, gastric endoscopy, video recordings, faecal samples, and behavioural observations were conducted to gather comprehensive data on the horses' response to the supplement or placebo.
The researchers found that the addition of a gastrointestinal support supplement had minimal impact on various factors, including concentrations of serum cortisol and gastrin, faecal and gastric pH, crib-bite counts, and the duration of cribbing bouts, according to the researchers.
Levels of cortisol, an indicator of stress in horses, showed no significant differences between the two treatments (supplement vs placebo) or among horses exhibiting cribbing behavior. Interestingly, among cribbing horses, those given the supplement exhibited more severe squamous (upper stomach) ulcers compared to horses receiving the placebo. Both faecal and stomach pH were simiilaracross horses and treatments, and
Non-cribbing horses did not display cribbing behaviour throughout the study.
Notably, for all cribbing horses, cribbing behaviour was most frequent around feeding time. However, the number of bites per cribbing bout and the duration of cribbing bouts were similar between the supplemented and placebo groups.
In summary, the researchers did not observe significant changes in gut physiology or cribbing behaviour among horses receiving the gut health supplement.
They conclude: “The findings challenge some prevailing assumptions and emphasize the need for comprehensive, longitudinal research in this field.”
For more details, see:
Ana M. Arias-Esquivel, Ana C. Cerqueira de Melo Vasco, Jill Lance, Lori K Warren, Luis A Rodriguez-Campos, Megan C. Lee, Christina N. Rodriguez, Carissa L Wickens,
Investigating the gastrointestinal physiology of mature horses with and without a history of cribbing behavior in response to feeding a digestive support supplement,
Journal of Equine Veterinary Science (2024) vol 132, 104964