Table 2. Summary of dietary nutrient requirement and utilization of rainbow trout, Oncorhychus mykiss (requirement expressed for dry feed except otherwise where mentioned).
Nutrient level		Life stage/size class
		Fry	Fingerling	Juvenile	Grower	Broodstock
Crude protein, % min		45–50	45	43	42	35–40
Crude protein, g/kg body weight/day
Amino acids, % min of dietary feed (dry matter basis)
	Arginine	2	2	2	2	2
	Histidine	0.7	0.7	0.7	0.7	0.7
	Isoleucine	0.8	0.8	0.8	0.8	0.8
	Leucine	1.4	1.4	1.4	1.4	1.4
	Lysine	1.8	1.8	1.8	1.8	1.8
	Methionine	1	1	1	1	1
	Phenylalanine	1.2	1.2	1.2	1.2	1.2
	Threonine	0.8	0.8	0.8	0.8	0.8
	Tryptophan	0.2	0.2	0.2	0.2	0.2
	Valine	1.3	1.3	1.3	1.3	1.3
Crude lipid, % min
Essential fatty acids, % min
	18:2n-6
	20:4n-6	0.5	0.5	0.5	0.5	0.5
	18:3n-3
	20:5n-3	1	1	1	1	1
	22:6n-3	0.5	0.5	0.5	0.5	0.5
Carbohydrate, % max		12	12	12	12	12
Crude fibre, % max		3	3	3	3	3
Gross energy, min kJ/g		15.5	15.5	15.5	15.5	15.5
Digestible energy, min kJ/g		15.5	15.5	15.5	15.5	15.5
Metabolizable energy, min kJ/g
Protein to energy ratio, mg/kJ		25	25	25	22	23
Minerals
Macroelements (%)
	Calcium, max	1	1	1	1	1
	Phosphorus, min	0.8	0.7	0.6	0.6	0.6
	Magnesium, min	0.05	0.05	0.05	0.05	0.05
	Sodium, min	0.06	0.06	0.06	0.06	0.06
Microelements, min mg/kg dry diet
	Potassium	0.7	0.7	0.7	0.7	0.7
	Iron	60	60	60	60	60
	Sulphur
	Chlorine
	Copper	3	3	3	3	3
	Manganese	13	13	13	13	13
	Zinc	30	30	30	30	30
	Cobalt
	Selenium	0.3	0.3	0.3	0.3	0.3
	Iodine	1.1	1.1	1.1	1.1	1.1
	Molybdenium
	Chromium
	Flourine
Vitamins, min IU/kg
	Vitamin A	2 500	2 500	2 500	2 500	2 500
	Vitamin D	2 400	2 400	2 400	2 000	2 000
Vitamins, min mg/kg
	Vitamin E	25–100	25–100	25–100	25–100	25–100
	Vitamin K	1	1	1	1	1
	Thiamine	10	10	10	10	10
	Riboflavin	5	5	5	5	5
	Pyridoxine	6	6	6	6	6
	Pantothenic acid	20	20	20	20	20
	Niacin	10	10	10	10	10
	Folic acid	2	2	2	2	2
	Vitamin B12	0.02	0.02	0.02	0.02	0.02
	Choline	800	800	800	800	800
	Inositol	300	300	300	300	300
	Biotin	0.15	0.15	0.15	0.15	0.15
	Ascorbic acid	40	40	40	40	40
* Requirements measured in fingerling and juvenile fish. Values for other life-history stages are estimates.
Data source: National Research Council (1993)