WORLD AQUACULTURE 67 Many alternative protein sources tested in fish, including soybeans, alfalfa and oilseed meals, contain a variety of antivitamin factors that might affect their efficiency as nutrient sources. Antivitamins are heat labile; therefore, these substances should not be of physiological significance in fish, provided the plant-derived resources being incorporated in diets are properly heat-treated. Most commercially available seed meals are heattreated to inactivate trypsin inhibitors and lectins and are also free from antivitamins. Phorbol esters, toxic substances found in Jatropha (physic nut) meal, act as a co-carcinogen and have a wide range of adverse biochemical and cellular effects in animals. Oxycarotenoids such as zeaxanthin and lutein present in corn-gluten meal reduce the acceptance of white-fleshed fish in certain markets by imparting the fillet with yellow pigmentation. Substitution for Fishmeal Plants are widely available and reasonably priced, encouraging the use of plant protein sources in aquafeeds. A wide variety of plant protein ingredients are promising candidates to replace fishmeal as a protein source in aquafeeds. These include oilseeds (soybean, jatropha, cottonseed and canola), legumes (lupin and pea), cereal grains (corn and wheat), and protein concentrate (soy, canola and lupin). The comparative proximate and essential amino acid compositions of different aquafeed ingredients are summarized in the Table 2. In general, plant protein sources are deficient in some essential amino acids and contain anti-nutritional factors. Therefore, the inclusion levels of raw or under-processed plant materials are restricted in aquafeeds. On the other hand, properly processed (CONTINUED ON PAGE 68) TABLE 2. Typical composition of commonly used aquaculture feed ingredients (Miller and Young 1977, Nwokolo 1987, NRC 1982, 1998, Glencross et al. 2007, Makkar et al. 2008, Makkar and Becker 2009). Ingredients Proximate composition (g/kg-1 dry matter) Essential amino acids (g/kg-1 dry matter) Dry Crude Total Ash Gross Arginine Histidine Isoleucine Leucine Lysine Methi- Phenyl- Threonine Valine matter protein lipid energy* onine alanine Fish meal1 917 770 68 142 21.3 43 25 28 55 46 21 29 32 34 Fish meal2 920 720 84 104 21.6 38 19 25 46 43 18 23 26 32 SE soybean meal 909 518 47 69 19.6 42 14 23 44 28 9 27 24 24 SE Canola meal 962 431 22 86 19.6 32 26 3 25 41 30 27 16 78 Ex canola meal 898 381 136 66 23.1 39 28 3 28 46 37 29 18 66 Yellow lupin 903 547 87 44 20.9 61 15 20 45 23 4 21 20 19 NL lupin 885 415 53 33 20.4 47 10 15 29 14 3 16 16 14 Peanut meal 928 481 13 58 20.3 67 16 19 32 20 5 29 14 20 Sunflower meal 930 422 29 76 20.7 36 11 17 26 12 7 20 13 23 Corn gluten meal 900 602 18 21 21.1 19 13 25 102 10 14 38 21 28 Cotton seed meal 900 414 18 64 20.6 45 12 13 25 17 7 22 14 18 Pea meal 928 252 13 38 16.4 19 11 14 41 27 6 19 17 14 Rapeseed meal 900 385 39 67 20.8 21 11 14 24 20 8 16 15 17 Wheat gluten 937 856 13 9 21.1 43 21 43 69 16 17 49 24 43 Wheat meal 941 145 16 14 18.7 6 3 4 9 3 7 2 4 5 DJKM 945 665 11 137 18.3 70 22 27 47 23 11 30 22 32 PPC 910 738 15 20 20.9 38 17 71 76 58 17 49 43 49 JPI 945 808 97 10 21.3 86 24 34 56 19 39 12 26 59 LPC 942 690 93 31 22.2 78 15 27 51 25 5 28 23 23 SPC 939 590 54 79 20.3 45 15 26 48 28 9 30 25 27 SPI 957 922 10 38 22.0 69 24 36 68 52 43 12 31 37 *MJ/kg; 1 Chilean anchovetta meal; 2 Herring; 3 Lupinus luteus (cv.Wodjil) kernel meal. NL lupin, narrow-leaf lupin Lupinus angustifolius (mixed cultivars) kernel meal; LPC, Lupinus angustifolius (mixed cultivars) protein concentrate; SE, solvent-extracted; Ex, Expeller. DJKM, detoxified Jatropha kernel meal; SPC, soybean protein concentrate; SPI, Soy protein isolate; JPI, Jatropha protein isolate; PPC, potato protein concentrate and LPC, Lupin protein concentrate.
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