Compared with terrestrial animal and plant protein sources, fish meal is unique in that it is not only an excellent and rich source of high quality protein containing, in ideal proportions, the ten essential amino acids (amino acids that cannot be synthesized by animals including fish and, therefore, must be supplied in the diet).
Fish meal is also a good source of essential fatty acids (present in the residual lipid in the meal), minerals and trace elements. Therefore, in choosing alternatives to fish meal, it is necessary to consider the amino acid profile and also other macro and micronutrients. |  | | | Figure: Essential amino acid analyses of rapeseed meal, data in % compared to fish meal. |
When formulating feeds, the supply of all essential amino acids in the right proportions is crucial. Even today, fish meal (FM) remains the major amino acid source in feeds for most European farmed fish. This is because FM has the right proportion of all the amino acids and also has other interesting properties such as excellent palatability.
Fish meals vary in quality depending on the source of the fish and the type of manufacturing processes involved. In general, good quality FMs used in aquaculture have high protein levels, above 66% of dry matter.
Compared to FM, there are few ingredients, such as corn gluten meal, wheat gluten or soy protein concentrate, that have similar high protein levels. Moreover, the amino acid profiles of each of these ingredients is different from that of FM. Consequently no single ingredient can totally replace FM and one has to use a mixture of ingredients to mimic the amino acid profile of FM.
Results of earlier projects such as PEPPA show that it is possible to reduce by 75% the FM levels in feeds for rainbow trout or gilthead seabream. Using various husbandry, physiological and metabolic criteria, it was shown that such replacements ensured that the growth, nutrient utilisation, health and reproductive performance of fish reared on low FM diets were similar to those of fish reared on high FM diets.
Aquamax Feeds should supply all the essential nutrients. Recognising that fish need nutrients, not ingredients, in the studies already under way in Aquamax with the different species, mixture of different protein sources have been used to replace FM to a large extent.
Table: The amino acid analyses of several pulses, oilseed meals and cereal proteins (unit:g/100g prot.)
| | Pulses | Oilseed meals | Cereal proteins |
| | | Peas | Lupin | Rapeseed
meal | Soybean
meal | Wheat
gluten | Corn gluten
meal | Fish meals | | Arginine | 8.3 | 11.8 | 6.8 | 7.2 | 3.3 | 3.0 | 5.8 | | Histidine | 1.5 | 3.1 | 2.6 | 1.9 | 2.0 | 1.6 | 2.1 | | Isoleucine | 4.0 | 3.8 | 3.8 | 4.7 | 3.9 | 4.2 | 4.5 | | Leucine | 7.1 | 7.2 | 4.5 | 8.2 | 7.1 | 18.8 | 7.7 | | Lysine | 6.1 | 4.2 | 6.6 | 6.3 | 1.7 | 1.9 | 6.8 | | Sulphur amino acids
(Methionine + Cystine) | 2.8 | 2.4 | 4.4 | 2.6 | 1.8 | 4.1 | 3.4 | | Aromatic amino acids
(Phenylalanine + Tyrosine) | 7.8 | 8.4 | 8.0 | 9.1 | 8.6 | 11.2 | 7.0 | | Threonine | 3.5 | 3.8 | 4.9 | 4.1 | 2.8 | 3.4 | 4.0 | | Tryptophan | 0.9 | 0.7 | 1.2 | 1.1 | 0.9 | 0.4 | 0.9 | | Valine | 5.7 | 4.2 | 3.7 | 4.4 | 4.3 | 4.0 | 5.3 |
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Fish feed 
