Measuring gastrointestinal pH and pressure in cribbing and non-cribbing horses with a wireless gastrointestinal monitoring capsule

s / Journal of Equine Veterinary Science 33 (2013) 321-399 355 drum using a tapered element oscillating microbalance sampler (1400a; Thermo Fisher Scientific, Waltham MA). Instantaneous TSP concentrations were recorded every 60 sec for 30 min. Measurements were averaged over 30 minutes; and the average expressed on a weight (kg) basis. Differences between preand post-steaming dust concentrations were evaluated using PROC MIXED of SAS with P 0.05 considered significant. Initial dust content measurements were different between the two hays; 758 and 406 mg/m3 per kg DM for MM and LM, respectively (P 1⁄4 0.030). Steaming reduced the dust content of the MM hay to 345 mg/m3 per kg DM (P 1⁄4 0.043); however, dust content in the LM hay was not significantly affected by steaming (257 mg/ m3 per kg DM, P 1⁄4 0.445). Limited data is available regarding typical, or acceptable, concentrations of dust in feedstuffs commonly fed to horses. However, steaming of the MM hay reduced dustiness to levels comparable to the LM hay, whichwas considered an acceptable hay for horses. Additional research needs to determine acceptable levels of dust; until then, results from this study indicate that steaming represents a viable management strategy for reducing dustiness in hay containing elevated dust levels. Measuring gastrointestinal pH and pressure in cribbing and non-cribbing horses with a wireless gastrointestinal monitoring capsule C.A. McCall , P.J. Tyler , L.S. Riggs , and W.H. McElhenney 3 Department of Animal Sciences, Auburn University, Auburn, AL 36849, 2 Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849, Department of Agricultural and Environmental Sciences, Tuskegee University, Tuskegee, AL 36088 Four mature geldings were used to evaluate differences in gastrointestinal pH and pressures in cribbing (n1⁄42) and non-cribbing horses (n1⁄42). Horses were maintained on pastures and brought into stalls 1 h prior to starting gastrointestinal monitoring. While on trial horses were given their usual concentrate ration and free-choice hayand water. A wireless gastrointestinal monitoring capsule (SmartPill Corp., Buffalo, New York 14203-1109), which recorded pH every 5 sec and pressure (mmHg) every 0.5 sec, was administered to each horse via nasogastric tube. A wireless receiver, enhanced to more easily capture capsule data signals through the horse’s bodymass, was attached to a flysheet worn by the horse. Data were recorded until the first of two outcomes occurred: 72 h passed or the capsule passed through the horse. One cribbing horse and one noncribbing horse were administered capsules on two separate occurrences to evaluate repeatability of measurements on different days. No discernible differences were found between days and these data were averaged to give one set of data points for each horse. A consistent pH change was used to determine capsule location within the gastrointestinal tract. Data were analyzed in a completely randomized design with treatments arranged as a 3X2 factorial with three gastrointestinal locations (stomach, small intestine, cecum/colon) and twobehavioral conditions (cribbing, noncribbing). Proc GLM analyses revealed no treatment differences (P>0.05) in pH or pressure in any gastrointestinal location for cribbing vs. non-cribbing horses. However, gastrointestinal locations did differ (P<0.005) in mean minimum pH (3.62 0.59, 6.77 0.46, and 6.13 0.46 for the stomach, small intestineandcecum/colon, respectively), median pH (4.47 0.53, 7.51 0.42 and 6.73 0.42 for the stomach small intestine and cecum/colon, respectively) and maximum pH (5.68 0.40, 7.98 0.32, 7.38 0.32 for the stomach, small intestine and cecum/colon, respectively) with the stomach consistently exhibiting lower pH values than the remainder of the tract. No significant differences were found between small intestinal pHmeasurements and that of the cecum/colon. No significant differences in pressure measurements were detected among the segments of the gastrointestinal tract. Because the gastrointestinal monitoring system was designed for human use, problems were encounteredwith its use in horses. Bodymass of these horses often prevented data capture, especially from the stomach and small intestine. Data capture was more successful in horses weighing under 500 kg. Also, on-board data receivers were not designed to withstand the punishment associated with equine use. Based on these results, a larger study is not warranted unless this system can be modified to accommodate a larger body mass.