Table 4.
Effects of dietary threonine levels on growth performance and biochemical variables in the plasma and liver of broiler progeny aged from 1 to 21 D.
| Thr supplementation (bold) and (total dietary content, %) | P-value2 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Variable | 0.00 (0.38) | 0.12 (0.50) | 0.24 (0.62) | 0.36 (0.74) | 0.48 (0.86) | 0.60 (0.98) | SEM1 | Thr | L | Q |
| Initial weight (g) | 40.3a,b | 40.7a | 40.2a,b | 39.9b | 40.8a | 40.6a,b | 0.10 | 0.05 | ||
| Final weight (g) | 382.6b | 391.2a,b | 410.7a | 379.1b | 393.9a,b | 400.4a,b | 3.22 | 0.04 | ||
| ADG (g) | 16.3b | 16.7a,b | 17.7a | 16.2b | 16.8a,b | 17.1a,b | 0.15 | 0.04 | ||
| ADFI (g) | 29.6 | 29.7 | 30.7 | 29.2 | 28.4 | 29.6 | 0.36 | 0.64 | ||
| FCR (kg feed/kg egg) | 1.78 | 1.78 | 1.79 | 1.81 | 1.69 | 1.73 | 0.02 | 0.60 | ||
| Livability (%) | 93.0 | 99.5 | 99.5 | 97.7 | 96.3 | 97.9 | 0.78 | 0.14 | 0.08 | |
| In plasma | ||||||||||
| Uric acid (umol/L) | 394.0 | 315.1 | 341.6 | 373.4 | 352.7 | 346.1 | 9.10 | 0.19 | ||
| In liver | ||||||||||
| GOT (U/g prot) | 20.4 | 20.4 | 21.9 | 22.0 | 23.7 | 20.3 | 0.47 | 0.23 | ||
| GPT (U/g prot) | 6.03 | 4.63 | 5.06 | 4.85 | 4.88 | 4.75 | 0.17 | 0.20 | ||
1
Means within each row with different superscripts are significantly different (P < 0.05). Standard error of the mean by ANOVA (n = 6).
2
Thr = treatment effect; when significant, linear (L) and quadratic (Q) effects were tested.
GOT: glutamic oxaloacetic transaminase; GPT: glutamic-pyruvic transaminase.