Effects of Dietary Protein-to-Energy Ratios on Growth, Immune Response, Antioxidative Capacity, Liver and Intestinal Histology, and Growth-Related Gene Expression in Hybrid Yellow Catfish (Pelteobagrus fulvidraco × Pelteobagrus vachelli )

Table 1

Formulations and analyzed composition of experimental diets.

P/E ratios	Dietary treatments
	84	88	90	93	95	96	99	103
Fish meal	220	220	220	220	220	220	220	220
Poultry by-product meal	70	70	110	70	110	70	110	110
Soya bean meal	195	195	230	195	230	195	230	230
Cottonseed protein meal	40	40	70	40	70	40	70	70
Cassava starch	0	0	40	0	40	0	40	40
Wheat flour	256.5	256.5	160	256.5	160	256.5	160	160
Soybean oil	110	90	110	70	90	50	70	50
Lecithin oil	10	10	10	10	10	10	10	10
Monocalcium phosphate	20	20	20	20	20	20	20	20
Deglued bone meal	51	71	2.5	91	22.5	111	42.5	62.5
Mildew preventive	1.3	1.3	1.3	1.3	1.3	1.3	1.3	1.3
Additive premix (V+M)	10	10	10	10	10	10	10	10
L-Lys hydrochloride	5	5	5	5	5	5	5	5
DL-met	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5
L-threonine	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5
Choline chloride (50%)	3	3	3	3	3	3	3	3
Lutein	3	3	3	3	3	3	3	3
Antioxidant	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2
Analyzed composition of diets
Dry matter	928.2	917.2	912.1	909.1	909.7	908.0	908.1	909.1
Ash	19.9	21.8	16.2	24.2	18.7	26.7	16.7	14.5
Crude protein	392.4	397.3	430.8	399.7	435.2	397.5	437.2	439.1
Crude lipid	168.5	150.3	165.7	128.7	148.5	111.7	128.1	114.6
Total starch	204.7	205.1	170.7	198.4	166.0	204.5	166.8	174
Gross energy kcal/g	4.66	4.48	4.76	4.29	4.56	4.13	4.40	4.26
P/E mg/kcal	84.20	88.68	90.50	93.17	95.43	96.24	99.36	103.07

Fish meal: 64.99% CP, 4604.64 kcal/kg CE, and 9% CL. Poultry by-product meal: 63.57% CP, 4814.97 kcal/kg CE, and 10.77% CL. Soya bean meal: 37.69% CP, 4324.06 kcal/kg CE, and 2.04% CL. Cottonseed protein meal: 60.56% CP, 4554.14 kcal/kg CE, and 1.62% CL. Cassava starch: 0.17% CS, 3780.52 kcal/kg CE, 0.3% CL, and 89.06% CS. Wheat flour: 17.50% CS, 4244.08 kcal/kg CE, 2.69% CL, 60.55% CS. Soybean oil: 9261.00 kcal/kg CE and 98% CL. Lecithin oil: 6860.70 kcal/kg CE and 72.6% CL. Deglued bone meal: 9.51% CP, 1069.49 kcal/kg CE, and 5.24% CL. L-lys hydrochloride: 86.4% CP, 5235.06 kcal/kg CE, and 78% Lys. DL-Met: 57.2% CP, 4785.38 kcal/kg CE, and 99% Met; L-threonine: 73.1% CP, 4130.15 kcal/kg CE, and 99% Thr, supplied by the ChengYi Co. Ltd., Guangzhou, China. Vitamin and mineral premix (mg-1 kg of product): vitamin A, 3000000 IU; vitamin D3,15000IU; vitamin E, 4000; vitamin K3, 450; vitamin B1, 800; vitamin B2, 850; vitamin B6, 600; vitamin B12, 1.5; folic acid, 130; inosi, 4000; L-ascorbate-2-phosphate, 11000; nicotinamide, 3000; calcium pantothenate, 1700; D-biotin, 15; D-calcium pantothenate, 1700; Cu, 650; Fe, 4500; Mn, 850; Zn, 5300; I, 120; Se, 35; Co, 100, supplied by the ChengYi Co. Ltd., Guangzhou, China.