The Optimum Dietary Phenylalanine Requirement of Hybrid Grouper (Epinephelusfuscoguttatus ♀ × Epinepheluslanceolatus ♂) Juveniles: Effects on Growth Performance, Gut Micromorphology, and Antioxidation

Table 1

Formulations and proximate composition of experimental diets (dry-matter basis).

Ingredients	Dietary Phe levels (g/kg)
	8.2	9.2	10.1	11.2	13.3	15.2	17.3
Peruvian fishmeal (anchovy)^a	210	210	210	210	210	210	210
Poutry byproduct meal^b	50	50	50	50	50	50	50
Amino acid mixture^c	255	255	255	255	255	255	255
L-phenylalanine	0	1.5	3	4.5	6	7.5	9
L-alanine	29.2	28.4	27.6	26.8	25.9	25.1	24.3
Chile fish oil (salmon)	42.5	42.5	42.5	42.5	42.5	42.5	42.5
Corn starch	233.7	233	232.3	231.6	231	230.3	229.6
Vitamin mixture^d	10	10	10	10	10	10	10
Mineral mixture^e	5	5	5	5	5	5	5
Cellulose	144.6	144.6	144.6	144.6	144.6	144.6	144.6
Carboxymethyl cellulose	20	20	20	20	20	20	20
Analyzed composition
Dry matter (g/kg)	911.9	921.7	917	913.7	929.4	928.4	914.7
CP (g/kg)	441	435.8	444.5	435.4	447.7	444.5	446.2
CL (g/kg)	67	67	67	67	67	67	68
Phe (g/kg)	8.2	9.2	10.1	11.2	13.3	15.2	17.3

^aThe ingredients were purchased from the Yongsheng Feed Corporation (Binzhou, China), and the proximate composition are as follows: moisture, 85.5; CP, 706.9; CL, 95.8. Amino acid composition (21 g Peruvian fishmeal): lysine 12.2; arginine 10.4; methionine 4.4; threonine 7.1; isoleucine 6.9; leucine 11.6; phenylalanine 6.7; valine 7.6; histidine 6.1; aspartic acid 14.3; serine 6.2; glutamic acid 20.2; glycine 11.2; alanine 9.7; cystine 1.1; tyrosine 5.4; proline 7.1. ^bPoutry byproduct meal (American Proteins Inc., USA): moisture, 39.9; CP, 641.4; CL, 146.7. Amino acid composition (5 g poutry byproduct meal): lysine 2.1; arginine 2.4; methionine 0.6; threonine 1.4; isoleucine 1.3; leucine 2.4; phenylalanine 1.4; valine 1.6; histidine 0.9; aspartic acid 2.8; serine 1.5; glutamic acid 4.6; glycine 3.2; alanine 2.4; cystine 0.4; tyrosine 0.9; proline 2.2. ^cAmino acid mixture(g/kg): arginine,23.7; methionine, 9.5; threonine, 3.0; isoleucine, 11.7; leucine, 18.4; valine, 6.5; histidine, 5.9; aspartic acid, 34.4; serine, 14.2; glumatic acid, 66.7; glycine, 17.4; cystine, 5.5; tyrosine, 11.1; proline, 13.9; lysine sulfate (550 g/kg): 13.2. ^dVitamin mixture and ^emineral mixture see [29].