| Gastrointestinal irritation has been implicated in crib-biting (CB) in horses. Eighteen horses, 9 CB and 9 non crib-biting (NCB), were used to determine (1) prevalence and severity of gastric mucosal damage, and (2) effect of concentrate feeding on circulating gastrin concentrations in CB and NCB horses. Endoscopic examinations (EE) of the squamous mucosa were performed and gastric fluid sampled alter 24-28 hr feed removal. Three days after EE, blood was collected at 1400 hrs on pasture, following 12-hr feed removal (0 min), and at 60 and 120 min after consuming 1 kg of a pelleted concentrate. There were no differences in number (P > 0.05) or severity (P > 0.05) of ulcers or prevalence of hyperkeratosis (P > 0.05) between CB and NCB. There was no difference (P = 0.87) in gastric pH of CB compared to NCB (3.92 vs. 3.78, respectively, SEM = 0.60). There was no effect of CB (P = 0.56) on serum gastrin concentration (14.22 vs. 12.16 pg/ml for CB and NCB, respectively, SEM = 2.46) with free access to hay and pasture. Serum gastrin concentration within CB was greater at times 60 and 120 min compared to 0 min (P < 0.01). Compared to 0 min, serum gastrin concentration in NCB tended to differ at 60 minutes (P = 0.07) and was greater at 120 minutes (P < 0.05). Serum gastrin concentration at 60 minutes was greater (P < 0.05) in CB compared to NCB. Compared to NCB, there was a trend for greater serum gastrin concentration in CB at 120 minutes post concentrate feeding (P = 0.06). The results suggest gastric mucosal damage is not associated with CB in mature horses maintained on pasture. Greater gastrin response to concentrate feeding in CB may indicate altered gastrointestinal function in CB, which could result in a more acidic gastric environment post concentrate feeding.;Weaving and crib-biting behavior (WCB) in horses are viewed as a management and welfare concern. A web-based questionnaire was developed to investigate WCB in Michigan horses. Responses from 293 individuals were received representing a total of 2,181 horses. The percentage of horses exhibiting weaving (W) and CB was 2.7% and 5.2%, respectively. The proportion of respondents attempting to stop CB (81.0%) was greater (P < 0.01) compared to W (37.5%). Methods employed to stop or reduce W included increased turn-out (21.4%) and provision of toys (14.3%). Cribbing collars (77.6%), alteration of CB surfaces (55.3%), and increased turn-out (54.1%) were used most frequently to stop or reduce CB. Many owners used a combination of methods. A negative association was identified between hours of daily turn-out and the probability of WCB (P < 0.01). Compared to horses allowed turn-out with conspecifics, the risk of CB was greater for horses with visual contact only (Adjusted odds ratio (OR) = 5.61) and for horses without social contact (Adjusted OR = 6.26). Contrary to previous studies, a larger daily amount of concentrate was associated with a decrease in the odds of W (P < 0.05) and CB (P < 0.01). Michigan horse owners expressed concern about WCB and attempted to control WCB. Additional research into the risk factors associated with WCB is needed, as well as careful documentation of the development of these behaviors in order to improve horse management and welfare. |
