Table 6.
Effects of dietary leucine level on the villus height, crypt depth and V:C ratio of broilers' ileum at different days.
| Item | Group |
|||
|---|---|---|---|---|
| 1.37TM | 1.77TM | 2.17TM | 2.57TM | |
| Villus height, μm | ||||
| d 7 | 220.55 ± 18.19 | 233.14 ± 19.12 | 239.39 ± 21.52 | 232.17 ± 16.76 |
| d 14 | 264.06 ± 22.01a | 302.63 ± 20.31b | 306.12 ± 9.42b | 295.11 ± 17.76b |
| d 21 | 362.62 ± 26.81ab | 372.00 ± 13.80ab | 395.85 ± 12.81b | 346.82 ± 31.16a |
| Crypt depth, μm | ||||
| d 7 | 67.21 ± 9.77 | 64.52 ± 2.56 | 71.12 ± 10.64 | 70.19 ± 9.70 |
| d 14 | 86.95 ± 8.94b | 76.94 ± 9.00ab | 67.14 ± 3.79a | 74.50 ± 10.32a |
| d 21 | 136.19 ± 16.82b | 98.46 ± 8.64a | 93.04 ± 1.94a | 122.41 ± 20.25b |
| V:C | ||||
| d 7 | 3.32 ± 0.30 | 3.61 ± 0.26 | 3.42 ± 0.52 | 3.34 ± 0.27 |
| d 14 | 3.05 ± 0.23a | 3.96 ± 0.28b | 4.57 ± 0.21c | 3.99 ± 0.32b |
| d 21 | 2.68 ± 0.28a | 3.80 ± 0.30b | 4.26 ± 0.12c | 2.88 ± 0.41a |
1.37TM = 1.37% leucine in the nutrient composition, etc; V:C = the ratio of villus height to crypt depth.
a,b Within a row, means with different superscripts differ significantly (P < 0.05).