The repeatability of an oral glucose test in ponies

Reasons for performing study - Insulin dysregulation can be difficult to diagnose from basal insulin and glucose concentrations, so a field-based oral glucose test (OGT) is preferred. However, the repeatability of this test has not been reported. Objectives - To determine the repeatability of an in-feed OGT in ponies and examine some factors affecting the palatability of the test meal. Study design - A repeated measures, longitudinal study. Methods - An in-feed OGT was performed at 08.00 h on 3 consecutive occasions under controlled conditions in 8 mixed breed ponies. d-glucose (0.75 g/kg bwt) was dissolved in water and combined with wheat bran and lucerne chaff. Blood samples were taken before and 90, 120, 180 min and 24 h after d-glucose. The repeatability of the test was analysed with repeated measures ANOVA. Insulin and glucose responses to d-glucose were also compared to an equivalent dose of dietary carbohydrate provided with a commercial grain mixture. Results - The overall insulin responses to the OGTs did not differ between tests. Individual insulin responses were more variable (P