Cottonseed Meal Protein Hydrolysate Improves the Growth Performance of Chinese Mitten Crab (Eriocheir sinensis) by Promoting the Muscle Growth and Molting Performance

Table 4

Effects of dietary cottonseed meal protein hydrolysate levels on the growth performance of E. sinensis.

Group	CPH0	CPH0.2	CPH0.4	CPH0.8	CPH1.6	CPH3.2	Polynomial contrasts
							Linear	Quadratic
IBW (g)	37.33 ± 0.67	37.40 ± 0.23	37.33 ± 0.24	37.33 ± 0.07	37.53 ± 0.35	37.00 ± 0.00	ns	ns
FBW (g)	60.50 ± 1.18^c	61.73 ± 0.59^bc	62.04 ± 0.21^bc	63.24 ± 0.31^abc	64.27 ± 0.38^ab	65.18 ± 0.60^a	0.00	0.00
WG^1 (%)	61.97 ± 3.11^c	65.02 ± 1.46^bc	66.80 ± 0.72^bc	69.78 ± 0.89^ab	70.99 ± 1.30^ab	76.16 ± 1.63^a	0.00	0.00
SR^2 (%)	67.50 ± 4.79^b	65.00 ± 2.89^b	82.50 ± 2.50^a	65.00 ± 2.89^b	72.50 ± 2.50^ab	67.50 ± 2.50^b	ns	ns
FCR^3	2.07 ± 0.34^a	1.94 ± 0.05^ab	1.88 ± 0.07^ab	1.96 ± 0.05^ab	1.82 ± 0.05^b	1.74 ± 0.05^b	0.00	0.01
FI^4 (g)	64.44 ± 8.01	78.29 ± 6.49	65.67 ± 10.23	83.00 ± 8.54	69.29 ± 4.10	72.14 ± 4.86	ns	ns
BPG^5 (g)	3.41 ± 0.14^d	3.51 ± 0.06^cd	3.78 ± 0.02^c	4.22 ± 0.04^b	4.41 ± 0.07^ab	4.64 ± 0.08^a	0.00	0.00
APU^6 (%)	6.83 ± 0.25^d	7.32 ± 0.17^cd	8.14 ± 0.32^c	8.56 ± 0.20^bc	9.49 ± 0.38^ab	10.22 ± 0.30^a	0.00	0.00

Values are means ± SEM of four replicates. Means in the same row with different superscript letters are significantly different (). ns, not significant. CPH, cottonseed meal protein hydrolysate; CPH0 to CPH3.2, dietary cotton meal replacement by 0%, 0.2%, 0.4%, 0.8%, 1.6%, and 3.2% of CPH. IBW, initial body weight; FBW, final body weight; WG, weight gain; SR, survival rate; FCR, feed conversion ratio; FI, feed intake; BPG, body protein gain; APU, apparent protein utilization. Calculations were carried out using the following formulas: ¹WG (%) = 100 × (final body weight–initial body weight)/initial body weight; ²SR (%) = 100 × final survival crab number/initial crab number; ³FCR = total diet fed/total weight gain; ⁴FI = total diet fed/crab number; ⁵BPG (g) = final amount of dry body protein–initial amount of dry body protein; ⁶APU (%) = 100 × BPG/dry protein intake; SEM, standard error of mean.