Table 3. Growth performance, feed utilization and relative insulin-like growth factors binding protein gene expression of juvenile Pacific white shrimp (Penaeus vannamei) (initial average weight: 0.46 g) fed the experimental diets for 8 weeks

Valine levels (g/kg)	FBW1)	WG2)	SGR3)	IGF-BP4)	PER5)	DFI6)	FCR7)	Survival (%)
2.7	1.33 ± 0.18c	187 ± 38.2c	1.42 ± 0.18b	1.00 ± 0.27c	0.81 ± 0.15b	0.055 ± 0.002	3.61 ± 0.73a	72.9 ± 14.2
5.1	1.38 ± 0.07bc	197 ± 15.0bc	1.47 ± 0.07ab	1.31 ± 0.22b	0.84 ± 0.07b	0.054 ± 0.001	3.38 ± 0.32ab	75.0 ± 9.62
8.7	1.55 ± 0.08a	236 ± 18.1a	1.63 ± 0.07a	1.80 ± 0.26a	0.99 ± 0.05a	0.054 ± 0.002	2.83 ± 0.15b	75.0 ± 6.80
12.1	1.53 ± 0.11ab	231 ± 24.0ab	1.61 ± 0.10a	1.26 ± 0.15bc	1.01 ± 0.07a	0.053 ± 0.002	2.83 ± 0.18b	77.1 ± 18.5
16.0	1.32 ± 0.08c	185 ± 15.5c	1.41 ± 0.07b	1.32 ± 0.21b	0.81 ± 0.08b	0.054 ± 0.002	3.50 ± 0.31a	77.1 ± 12.5
Pr > F*
ANOVA	0.02	0.18	0.02	0.01	0.01	0.85	0.03	0.98
Linear	0.43	0.43	0.42	0.10	0.30	0.71	0.24	0.61
Quadratic	0.00	0.00	0.00	0.00	0.93	0.43	0.01	0.93

The experimental diets were added with valine by 2.7, 5.1, 8.7, 12.1 or 16.0 g/kg diet.
Values are mean of quadruplicate and presented as mean ± SD.
Values with different superscripts in the same column are significantly different (p < 0.05).
Significance probability associate with the F-statistic.
Final body weight (g).
Weight gain (%) = (final body weight-initial body weight) / initial body weight × 100.
Specific growth rate (%) = (log_e final body weight – log_e initial body weight) / days × 100.
Insulin-like growth factors binding protein relative gene expression level.
Protein efficiency ratio = wet weight gain / total protein given.
Daily feed intake (g / shrimp / day) = dry feed consumed (g) / shrimp number / day
Feed conversion ratio = dry feed intake / wet weight gain.
ANOVA, analysis of variance.