Effects of Transport and Feeding Strategies Before Transportation on Redox Homeostasis and Gastric Ulceration in Horses.

Transportation may lead to oxidative stress (OS) and gastric ulceration in horses, and optimal feed management before, or during, transportation is unclear. This study aimed to evaluate the effects of transportation after three different feeding strategies on OS and to explore possible associations between OS and equine gastric ulcer syndrome (EGUS). Twenty-six mares were transported by truck for 12 hours without food or water. Horses were randomly divided into 3 groups; (1) fed 1 hour before departure (BD), (2) fed 6 hours BD, (3) fed 12 hours BD. Clinical examinations and blood collections were performed at approximately 4 hours BD (T0), at unloading (T1), 8 hours (T2) and 60 hours (T3) after unloading. Gastroscopy was conducted prior to departure, and at T1 and T3. Although OS parameters remained in the normal range, transportation was associated with increased reactive oxygen metabolites (ROMS) at unloading (P=0.004), with differences between horses fed 1 hour and 12 hours BD (P < .05). The level of total antioxidant (PTAS) was affected by both transportation and feeding strategy (P = 0.019), with horses fed 1 hour BD demonstrating greater PTAS at T = 0, and a different response in comparison with the other groups and the literature. Nine horses demonstrated clinically significant ulceration of the squamous mucosa at T1 but, although weak correlations were evident between OS parameters and ulcer scores, univariate logistic regression showed no associations. This study suggests that feed management prior to a long journey (12 hours) may affect oxidative balance. Further studies are needed to understand the nexus between feed management before and during transport, transport-related OS and EGUS.