More Information About Cribbing Horses

Cribbing (or crib-biting), a behavior in which horses set their incisors against a solid surface and appear to gulp air while making a grunting noise, has been an aggravation to owners and a puzzle to researchers. Cribbing horses sometimes lose weight and have more frequent colic episodes than noncribbers, and sale prices for cribbers are usually lower than for horses without this behavior. A recent study conducted by scientists from Michigan State University, Auburn University, and Tuskegee University showed that horses that crib produced more gastrin after consuming meals of concentrated feed than noncribbing horses did. Gastrin is a hormone that stimulates the production of stomach acid.

Nine mature horses that cribbed and nine mature horses that were not cribbers were used in the study. The horses were pastured, had free access to hay, and were given two daily meals of a pelleted concentrate. Cribbing behavior (number of bites and amount of time spent cribbing) was noted for 24 hours. Endoscopic examinations of the squamous mucosa were performed and gastric fluid was sampled 24 to 28 hours following feed removal. Blood samples were collected 12 hours after feed removal and at 60 and 120 minutes after the horses consumed one kilogram of feed.

No differences were found in the number or severity of ulcers or in baseline gastric pH between horses in the two groups. After feeding, however, serum gastrin concentration was higher in the cribbers than in noncribbing horses. There was no association between cribbing and gastric mucosal damage in horses kept on pasture.