TABLE 4.
Glucose parameters of oral glucose tolerance tests (OGTTs) performed in Shetland pony mares on a control or high‐energy (HE; 200% of energy requirements) diet for 24 weeks (2014), 17 weeks hay‐only (winter break 2014‐2015), and another 29 weeks control or HE diet (2015)
| Mean basal plasma glucose concentration (mmol/L) (SD) | Mean peak plasma glucose concentration (mmol/L) (SD) | Median time of peak glucose concentration (range) | Mean (SD) area under the curve for glucose (mmol/L × min) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 2014 | Dietary period | Control | HE | Control | HE | Control | HE | Control | HE |
| OGTT 0 | 0 | 4.5 (.42) | 4.4 (.59) | 9.6 (1.6) | 9.2 (1.2) | 90 (60‐90) | 90 (90‐180) | 2197 (424) | 2194 (344) |
| OGTT 1 | 1 | 4.5 (.48) | 4.7 (.40) | 10.3 (1.7) | 9.0 (1.8) | 105 (60‐120) | 60 (30‐90) | 2419 (488)g | 1705 (247)h |
| OGTT 2 | 2 | 4.6 (.34) | 4.8 (.40) | 10.4 (2.1) | 9.5 (2.1) | 105 (60‐120) | 60 (60‐90) | 2456 (594)i | 1799 (300)j |
| OGTT 3 | 3 | 4.4 (.33)a | 5.1 (.60)b | 9.5 (2.0) | 9.9 (2.6) | 120 (60‐120) | 60 (30‐90) | 2181 (528) | 1823 (317) |
| OGTT 4 | 4 | 4.2 (.17)c | 4.9 (.30)d | 9.8 (1.3) | 8.7 (1.4) | 120 (90‐120) | 60 (30‐90) | 2261 (245) | 1754 (182) |
| 2015 | |||||||||
| OGTT 0 | 5 | 4.7 (.23) | 4.3 (.41) | 9.6 (1.34) | 7.9 (.98) | 120 (90‐180) | 120 (60‐120) | 2445 (417) | 2026 (195) |
| OGTT 1 | 6 | 4.5 (.20) | 4.6 (.09) | 10.5 (1.3) | 9.3 (.62) | 120 (90‐180) | 75 (60‐90) | 2613 (386) | 1793 (92) |
| OGTT 2 | 7 | 4.3 (.24)e | 5.0 (.30)f | 10.3 (1.3) | 9.7 (1.54) | 120 (90‐180) | 75 (60‐90) | 2552 (390) | 1889 (196) |
| OGTT 3 | 8 | 4.3 (0) | 4.9 (0) | 7.3 (1.8) | 8.8 (1.52) | 120 (90‐120) | 75 (60‐90) | 1994 (422) | 1760 (245) |
Note: 2014: 4 control, 7 HE ponies (period 2, n = 5 HE); 2015: 6 control, 4 HE ponies (period 8, n = 3 control). Different superscripts within the same row indicate significance at P < .05; ab P = .02; cd P = .001; ef P = .02; gh P = .002; ij P = .006.