Table 1. Recommended dietary protein levels for various sizes of catfish. Fish weight Dietary requirement g/fish lb/1,000 fish % 0.02- 0.25 0.04- 0.55 52 0.25- 1.5 0.55- 3.3 48 1.5 - 5.0 3.3 -11.0 44 5.0 -20.0 11.0 -44.0 40 20.0 -27.0 44.0 -60.0 35 27 and up 60 and up 26-32 Table 2. Amino acid requirements of channel catfish.a Amino acid Requirement (% of dietary protein) Arginine 4.3 Histidine 1.5 Isoleucine 2.6 Leucine 3.5 Lysine 5.1 Methionine + cystine 2.3 Phenylalnine + tyrosine 5.0 Threonine 2.0 Tryptophan 0.5 Valine 3.0 aFrom NRC (1993). Nutrient Requirements of Fish. National Research Council. National Academy Press. Washington, DC. Table 3. Vitamin deficiency signs and minimum dietary levels required to prevent signs of deficiency in catfish.a Vitamin Deficiency signs Units (ppm or IU/lb) Requirement Fat solubleA Exophthalmia, edema, acities IU 450-900 D Low bone ash IU 110-220 E Skin depigmentation, exudative diathesis, muscle dystrophy, erythrocyte hemolysis, splenic and pancreatic hemosiderosis IU 23 K Skin hemorrhage, prolonged clotting time ppm R Water solubleThiamin Dark skin color, neurological disorders ppm 1.0 Riboflavin Short-body dwarfism ppm 9.0 Pyridoxine Greenish blue coloration, tetany, nervous disorders ppm 3.0 Pantothenic acid Clubbed gills, anemia, eroded skin, lower jaw, fins, and barbels ppm 15 Niacin Anemia, lesions of skin and fins, exophthalmia ppm 14 Biotin Anemia, skin depigmentation, reduced liver pyruvate carboxylase activity ppm R Folic acidb Reduced hematocrit ppm 1.5 B12 Reduced hematocrit ppm R Cholinec Hemorrhagic kidney and intestine, fatty liver ppm 400 Inositol None demonstrated ppm NR Ascorbic acid Reduced hematocrit, scoliosis, lordosis, increased susceptibility to bacterial infections, reduced bone collagen formation, internal and external hemorrhage ppm 60 aAdapted from Robinson, E. H. 1989. Channel catfish nutrition. Reviews in Aquatic Sciences 1:365-391. Anorexia, reduced weight gain, and mortality are common vitamin deficiency signs; thus, are not included in the table. R and NR refer to required and not required, respectively. bFrom National Research Council. 1993. Nutrient Requirement of Fish. National Academy Press, Washington, DC. cDetermined using diets marginal in methionine and based on liver lipid concentration. Table 4. Mineral deficiency signs and minimum dietary levels required to prevent deficiency signs in catfish.a Mineral Deficiency Signs Requirements Macrominerals Calciumb Reduced bone ash <0.1%, 0.45% Phosphorusc Reduced bone mineralization 0.40% Magnesium Muscle flaccidity, sluggishness, reduced bone, serum, and whole body magnesium 0.04% Sodium ND ND Potassiumd ND 0.26% Chloride ND ND Sulfur ND ND Microminerals Cobalt ND ND Iodine ND ND Zince Reduced serum zinc and serum alkaline phosphatase activity, reduced bone zinc and calcium concentrations 20 ppm Selenium Reduced liver and plasma selenium-dependent glutathione peroxidase activities 0.25 ppm Manganesee None 2.4 ppm Iron Reduced hemoglobin, hematocrit, erythrocyte count, reduced serum iron and transferrin saturation levels 20 ppm Copper Reduced hepatic copper-zinc superoxide dismutase, reduced heart cytochrome oxidase activities 4.8 ppm aAdapted from Robinson, E.H. 1989. Channel catfish nutrition. Reviews in Aquatic Sciences 1:365-391. Anorexia, reduced weight gain,and mortality are not listed as deficiency signs since they are common deficiency signs of several minerals. Minerals listed as not determined are assumed to be required. ND refers to not determined. bDeficiency cannot be demonstrated in catfish reared in water containing sufficient calcium. cRequirement expressed on an available basis. dWilson R. P. and G. El Naggar. 1992. Potassium requirement of fingerling channel catfish, Ictalurus punctatus. Aquaculture 108:169-175. Requirement based on whole body potassium balance. eRequirement will increase in presence of phytic acid. Table 5. Average apparent protein digestibility coefficients for catfish.a Feedstuff International feed number Percentage digestibility Alfalfa meal (17%) 1-00-023 13a Blood meal 5-00-381 74c Corn, grain 4-02-935 60a, 97b Corn, cooked 66a Corn, gluten meal 5-04-900 92c Cottonseed meal 5-01-621 81a, 83b Fish, anchovy meal 5-01-985 90a Fish, menhaden meal 5-02-009 87a, 85b, 70c, 86c Meat meal w/bone 5-00-388 75a, 61b, 82c Peanut meal 5-03-640 74b, 86c Poultry, byproduct meal 5-04-798 65c Poultry, feather meal 5-03-795 74a Rice, bran 4-03-928 73b Rice, mill feed 63b Soybean meal (44%) 5-04-604 77a Soybean meal (48%) 5-04-612 84a, 97b, 85c Wheat, bran 4-05-190 82a Wheat, grain 4-05-268 84a, 92b Wheat, shorts 4-05-201 72a aCruz, E.M. 1975. Determination of nutrient digestibility in various classes of natural and purified feed materials for channel catfish.Ph.D. Dissertation, Auburn University, Auburn, AL. bWilson, R.P., and W.E. Poe. 1985. Apparent digestible protein and energy coefficients of common feed ingredients for channel catfish.Progressive Fish-Culturist 47:154-158. cBrown, P.B., R.J. Strange, and K.R. Robbins. 1985. Protein digestion coefficients for yearling channel catfish fed high protein feedstuffs. Progressive Fish-Culturist 47:94-97. Table 6. Average apparent amino acid availabilities (expressed as a percentage) for various feedstuffs determined for catfish.a Amino acid Peanutb meal Soybeanb meal Meat + bonebmeal Feedstuff Menhaden fishb meal Cornc Cottonseedb meal Ricec bran Wheatc middlings Ala 88.9±0.5 79.0±2.8 70.9±3.0 87.3±1.5 78.2±1.0 70.4±1.3 82.0±0.9 84.9±0.9 Arg 96.6±0.2 95.4±0.7 86.1±3.4 89.2±0.7 74.2±0.2 89.6±0.2 91.0±1.1 91.7±0.5 Asp 88.0±0.4 79.3±1.4 57.3±0.5 74.1±1.8 53.9±3.1 79.3±0.5 82.4±0.7 82.8±2.7 Glu 90.3±1.0 81.9±1.0 72.6±3.8 82.6±0.1 81.4±1.6 84.1±0.3 88.8±0.4 92.3±0.5 Gly 78.4±0.3 71.9±2.8 65.6±4.7 83.1±1.2 53.1±3.2 73.5±0.6 80.0±0.9 85.2±0.4 His 83.0±0.6 83.6±1.2 74.8±2.0 79.3±2.2 78.4±0.6 77.2±2.0 70.4±2.1 87.4±1.2 Ile 89.7±0.2 77.6±4.0 77.0±5.2 84.8±1.0 57.3±3.4 68.9±0.6 81.4±0.9 81.8±1.9 Leu 91.9±0.1 81.0±3.4 79.4±3.1 86.2±0.6 81.8±1.0 73.5±0.7 84.1±0.9 84.6±1.3 Lys 85.9±0.5 90.9±1.3 81.6±2.6 82.5±1.2 69.1±4.8 66.2±1.2 81.3±0.3 85.9±2.1 Met 84.8±0.2 80.4±2.1 76.4±3.7 80.8±0.3 61.7±4.9 72.5±0.9 81.9±0.8 76.7±2.4 Phe 93.2±0.3 81.3±4.5 82.2±3.0 84.1±1.1 73.1±7.2 81.4±0.4 82.9±3.5 87.2±1.1 Pro 88.0±1.3 77.1±2.1 76.1±4.0 80.0±0.6 78.4±1.0 73.4±0.3 79.5±1.4 88.3±0.5 Ser 87.3±0.4 85.0±0.5 63.7±0.1 80.7±1.9 63.9±1.4 77.4±1.4 82.0±0.6 83.0±2.3 Thr 86.6±0.5 77.5±1.3 69.9±3.2 83.3±1.7 53.9±3.9 71.8±0.4 77.3±3.6 78.8±3.2 Tyr 91.4±0.3 78.7±2.6 77.6±3.7 84.8±1.4 68.7±5.0 69.2±2.6 86.7±3.2 83.0±2.0 Val 89.6±0.2 75.5±3.7 77.5±2.9 84.0±0.6 64.9±4.6 73.2±0.3 83.2±0.6 84.5±0.7 Avg 88.4 81.0 74.3 82.9 68.3 75.1 82.2 84.9 aMean ± SEM. Data from: Wilson, R.P. and E.H. Robinson. 1982. Protein and amino acid nutrition for channel catfish. Mississippi Agricultural and Forestry Experiment Station Information Bulletin 25. bDetermined after ad libitum feeding test diets. cDetermined after force-feeding test diets. Table 7. Average percentage apparent digestible energy determined for catfish.a Feedstuff International Percent digestibilityfeed number Alfalfa meal (17%) 1-00-023 16a Corn, grain 4-02-935 26a, 57b Corn (cooked) 59a Cottonseed meal 5-01-621 56a, 80b Meat meal w/bone 5-00-388 81a, 76b Fish, menhaden meal 5-02-009 85a, 92b Peanut meal 5-03-650 76b Poultry, feather meal 5-03-795 67a Rice, bran 4-03-928 50b Rice, mill feed 14b Soybean meal (44%) 5-04-604 56a Soybean meal (48%) 5-04-612 72a Wheat, bran 4-05-190 56a Wheat, grain 4-05-268 60a, 63b aCruz, E.M. 1975. Determination of nutrient digestibility in various classes of natural and purified feed materials for channel catfish. Ph.D. Dissertation, Auburn University, Auburn, AL. bWilson, R.P. and W.E. Poe. 1985. Apparent digestible protein and energy coefficients of common feed ingredients for channel catfish. Progressive Fish-Culturist 47:154-158. Table 8. Average apparent digestion coefficients of lipids and carbohydrates determined for catfish.a Feed sources International feed number Percentage digestibility Lipid Carbohydrate Fish, oil 97 Fish, anchovy meal 5-01-985 97 Meat meal w/bone 5-03-388 77 Poultry, feather meal 5-03-795 83 Soybean meal (44%) 5-04-604 81 Cottonseed meal 5-01-621 81 17 Wheat, grain 4-02-268 96 59 Uncooked corn (30% of diet) 4-02-935 76 66 Uncooked corn (60% of diet) 4-02-935 59 Cooked corn (30% of diet) 96 78 Cooked corn (60% of diet) 62 aCruz, E.M. 1975. Determination of nutrient digestibility in various classes of natural and purified feed materials for channel catfish. Ph.D. Dissertation, Auburn University, Auburn, AL. Table 9. Average percentage apparent availability of phosphorus determined for catfish. Source International feed number Availability Phosphates  Sodium phosphate,    mono basic 6-04-288 90a  Calcium phosphate,    monobasic 6-01-082 94a    dibasic 6-01-080 65a, 82b    defluorinated 6-01-780 82b Animal meals  Anchovy 5-01-985 40a  Menhaden 5-02-009 39a, 75b  Meat & bone/blood -- 84b Purified protein sources  Egg albumin 71c  Casein 5-01-162 90c Plant sources  Wheat, middlings 4-05-205 28a, 38b  Corn, grain 4-02-935 25a  Soybean meal (44%) 5-04-604 50a  Soybean meal (48%) 5-04-612 54a, 49b, 29c  Cottonseed meal (41%) 5-01-621 43b aFrom Lovell, R. T. 1978. Dietary phosphorus requirement of channel catfish (Ictalurus punctatus). Transactions of the American Fisheries Society 197:617-621. bUnpublished data from Delta Research and Extension Center. Based on weight gain of fish compared to a reference diet containing 0.4% available phosphorus from monobasic sodium phosphate. Weight gain appeared to be a more reliable indicator than did bone phosphorus concentrations. cFrom Wilson, R.P., E.H. Robinson, D.M. Gatlin III, and W.E. Poe. 1982. Dietary phosphorus requirement of channel catfish. Journal of Nutrition 112:1197-1202. Table 10. Feed ingredients used in commercial catfish feeds.a Feed ingredient Selected characteristics % Comments Dry matter Crude protein Crude fat Crude fiber Lys Met + Cys Protein supplements: Soybean meal (dehulled, solvent) 89.3 48 1 3 3.2 1.5 Major protein source used in catfish feeds. Is a high-quality protein. Contains antinutritional factors which are destroyed by heating. Palatable to catfish. Cottonseed meal (direct solvent) 90.4 41 2.1 11.3 1.76 1.1 Used sparingly in catfish feeds. Up to 20% CSM can be used without detrimental effects. Higher levels can be used if supplemented with lysine. Highly palatable to catfish. Contains free gossypol which can be toxic to animals. Feeds containing <0.09% free gossypol are not detrimental to catfish. Deficient in lysine and lysine availability reduced by binding to free gossypol. Peanut meal (mech extd) 91.8 45 5 12 1.55 1.1 Deficient in lysine. Levels used in catfish feed restricted to about 15-20% without lysine supplementation. Fish mealb (menhaden) 92 62 10.2 1 4.7 2.4 Good source of indispensable amino acids, phosphorus, and digestible energy. May also provide essential fatty acids. Highly palatable to catfish. Growout feeds for catfish generally contain 2 to 4% fish meal. Meat and bone meal 92.6 50 8.5 2.8 2.6 1 Good source of calcium and phosphorus. High in ash, which limits its use somewhat because of possibility of mineral imbalances. Maximum level recommended for catfish feeds is 15%. Blood meal blood meal 91 85 1 1 6.9 1.6 Flash or spray-dried blood meal have been used. Excellent source of lysine, but is deficient in methionine. Up to 5% can be used as lysine supplement. Generally used in combination with meat meals. Catfish meal offal 90 58 11 -- 4.19 1.9 Prepared from catfish processing waste. Good source of calcium, phosphorus, and energy. Seldom used because of lack of general availability. Soybeans (full-fat cooked) 90 38 18 5 2.4 1.1 Rarely used in catfish feeds, primarily because of high fat content. A limited amount can be used as long as total fat level in feed doesn't exceed about 6%. Energy supplements: Cornc (yellow, grain) 88 8.9 3.5 2.9 0.22 0.3 Abundant and relatively inexpensive source of energy. Cooking improves energy digestibility. Aids in pelleting and improves floatability of feed. Wheat (grain) 88 13.5 1.9 3 0.4 0.6 Generally used sparingly in catfish feeds because corn is less expensive. Is used at rate of 3 to 4% to improve binding of feed pellet. Wheat (middlings) 89 17.7 3.6 7 0.6 0.3 Used at levels up to 15 to 30% in some catfish feeds. Improves pellet binding. Nutritional value to catfish as good or better than corn and wheat grain. Rice (bran) 91 13.5 12.5 13 0.5 0.3 Used at low levels (3 to 5%) because of high fat and fiber levels. Fish oil catfish) -- -- 100 -- -- -- Fat extracted from processing waste. About 2% is sprayed on top of finished feed. Good energy source and used to reduce feed dust. Fish oil (menhaden) -- -- 100 -- -- -- Good source of essential fatty acids and energy. Also used to reduce feed dust by spraying on finished feed pellet. Used at a rate of <1 %. May reduce survival of fish exposed to ESC. Fat (animal or vegetable) 99.5 -- 99.4 -- -- -- Generally highly digestible. May not supply essential fatty acids. Spray on top of finished feed at rate of 1 to 2% to reduce feed dust. Vitamin Supplements: Vitamin premix -- -- -- -- -- -- Meet recommendations given in Table 11. Mineral Supplements: Mineral premix -- -- -- -- -- -- Meet recommendations given in Table 11. Dicalcium or defluorinated phosphates -- -- -- -- -- -- Used as a phosphorus source at a rate of 1 to 2%. Phosphorus from these sources is about 80% digestible to catfish. Pellet bindersd -- -- -- -- -- -- Generally natural binders in grains are sufficient for extruded feeds. Some feed manufacturers add about 2 to 2.5% processed milo as a binder in extruded feeds. Various binders have been used in pelleted (sinking) feeds, including lignosulfonates, bentonites, and processed milo. aAdapted from Robinson, E.H. 1990. Feed, feed processing, and feeding of catfish. Technical Bulletin, Takeda, Inc. bOther fish meals may be used. cCorn screenings are often used instead of corn grain. dIf processed milo is used as a binder, it has nutritive value of milo grain. Table 11. Nutrients recommended for catfish grow-out feeds.a Recommended Units Comments Nutrient level Protein 26-32 % May vary depending on fish size, water temperature, dietary energy level, management practices, etc. Levels as low as 16% have provided for good weight gain. Indispensable amino acids: % of protein Generally, if lysine and sulfur amino acid requirements are met other amino acids will be adequate, at least when using feedstuffs commonly used in catfish feeds. Cystine can replace about 60% of methionine requirement. Tyrosine can replace about 50% of phenylalanine requirement. Synthetic amino acids can be used to supplement deficient proteins. Arginine 4.3 Histidine 1.5 Isoleucine 2.6 Leucine 3.5 Lysine 5.1 Methionine 2.3 Phenylalanine 5.0 Threonine 2.0 Tryptophan 0.5 Valine 3.0 Energy, digestible 8-10 kcal/g protein Use carbohydrate and lipid (fats or oils) as energy to spare protein for growth. Lipid <6.0 % Optimum level not known. Need enough to supply essential fatty acids. Consider effects of lipid on product quality and constraints of feed manufacture. Mixture of animal and vegetable lipids, catfish