F. GUILLAUME
1. INTRODUCTION
Long ago, the choice of raw materials was almost the only unique preoccupation in nutrition, before the scientific era came into being, nutrition dealt with nothing more than the choice of the appropriate food, and eventually the ration required. The study of food requirements, their digestive and metabolic utilization relagated the choice of raw materials to application level. This choice remains however very important for the success in the rearing results and it has even progressively entailed considerable scope in food chemistry research and is now included in animal food industry.
2. GENERALITIES
2.1. Definition
The definition of simple food or raw meterials, intended for compound food manufacture is not unique. Some time ago, the principal trend insisted on the properties of food to stimulate or slow down the peristalsis of the digestive tract along with its action on the other physiological functions. Today, we tend to consider its as simple sources of nutriments (energetic, proteic, vitaminic, mineral); the composition tables employed for the formulation only includes these latter elements. In fact, food raw materials are not only sources of nutriments, but also or inert essential elements (especially cellulose or fibres in general), antinutriments, factors with a certain toxicity, substances with a pharmacodynamic effect, appetence or inappetance factors, etc… To these natural compounds must be added the more or less systematic contaminants such has living organisms (bacteria, fungis, acardia), chemical contaminants derived from human activity (heavy metals, organochlorine, organophosphorus, etc…) or of natural origin (mycotoxins). Finally, other very important characteristics must be taken into account: the physical properties of raw materials, for the example the way in which they are easily mixed and agglomerated, etc…, in other words their technological properties.
2.2. The choice of raw materials
The choice of raw materials concerning feeding on general, is based on two axes: the empiric knowledge on one hand, and the sciences of nutrition, on the other. Empirism and tradition have led to the acquisition of appetizing products which are reliable or simply cheap or easy to find, much to the detriment of new food sources, suitable for advantageous combinations which can however be very complex and require treatment before hand. The actual scientific knowledge concerning the requirements of a species can be taken into account today, in less expensive formulation programmes. In theory, these programmes permit the selection of all the economical advantageous raw materials and to reject those which are two costly and even indicate for the latter the “interest price”at which their employment should become interesting.
In practice, these programmes very often only take into account the raw material tenor in nutriments or in a few other components such cellulose or ash. For numerous properties such as appetence, technological characteristics, there are neither quantitative nor additive criteria at disposal which can be employed directly in linear programming. One can certainly take this into account indirectly through the technical constraints by imposing for example a minimum threshold or the complete opposite, a maximum threshold of such and such ingredient. But low costing formulation through linear programming is still greatly limited, especially in cases where the qualitative requirements of the species are not well known and this is the case of the aquaculture species such has marine fish even more so crustaceans.
In practice, the choice of raw materials must always be taken in two steps, in other words, a scientific confrontation with the results remarked in situ and an allowance made for the empiric data obtained through practice.
2.3. Classification
Raw materials can be classed in many different ways: in taking into account their origin (vegetables, animal, bicrobial-in general, mineral, chemical), their main chemical characteristics (cellulosic food, amylaceous food, fat matter, protein sources, etc…). We shall adopt a combined classification which shall take into account the origin of the products, the species from which they were obtained along with the technological treatments which they were submitted to.
There or not many raw materials of animal origin (a few dozen), but those of vegetable origin most likely to be employed in aquaculture can be counted in hundreds. The report can only deal with a limited part of the above.
3. PRINCIPAL NUTRIMENTS REQUIRED
3.1. Relative importance
The principal elements which are taken into account in linear programming are, energy (expressed in digestable, metabolisable energy) proteins and essential amino-acids, lipids and essential fatty acids, phosphorus and calcium along with occasionally, raw cellulose, certain vitamins, carotenoids. We can impose for each one of these elements either a maximum or intermittant limits. In general, the most expensive among these elements are firstly energy and then proteins. We can remark that the priority for energy in comparison to protein, results partly from the establishment method for the diets we use, this method dating back to RUBNER, at the end of the 19th century. Indeed, the energy of the diet is that of all nutriments, including proteins which in this way, contributes in outclassing all the other sources of energy which afterwards will be counted one by one as sources of amino-acids. Whatever the case, the most expensive elements in a ration is energy and the principal plastic nutriments: protides, On the contrary, minor elements from a quantitative viewpoint, vitamins and mineral oligo-elements are very low costing at formulation level so that, for security reasons, vitamin and mineral premixes are nearly always added to the complete diet. In other words, it is cheaper to add synthetic vitamins to food than to divide into doses those of raw materials, while taking into account the requirements of the animals. Due to this, the vitamin in linear programming is very often omitted expect in certain cases, so as to know the total inputs and eventual excesses. The essential fatty acids and phosphorus which are utilized, hold intermediary positions between those of energy or proteins and those of vitamins or oligo-elements.
In theory, it is important not only to consider the gross inputs of proteins, glucids or lipids but to take into account at the same time the precise nature of the basic components (amino acids, simple sugars, fatty acids, etc…) and their availability. This is a complex problem which has already been discussed by somebody else during this session. Let us however, recall a few of the most important points:
3.1.1. The digestibility of nutriments is still quite unknown for marine animals. The “digestible protein” taken from old tables (pepsic digestibility in victor) is hardly ever employed. Only “raw”elements are at present utilizable in linear programming.
3.1.2. It is always preferable to replace the high class nutriments (proteins, glucids, lipids) by their components or better still to use both at same time.
3.1.2.1. Essential amino-acids and principally those which are scarce in the food eaten by animals (lysine and methionin) weigh much more then the non-indispensable amino-acids. but this priority is not as evident in fish, which in any case always use a great quantity of amino-acids for energetic purposes.
3.1.2.2. There will be always great uncertainty regarding glucids, as long as only the nitrogen free extractive is maintained for the estimation of the “total glucids”. Evan for real glucids such as starch, great differences in digestibility can be remarked, depending on the nature of the molecule, that of the strarch grain, technological treatments that the raw materials as been submitted to, etc… To take all these parameters into consideration, is still difficult in fish culture feeding.
3.1.2.3. Among the lipid components, fatty acids at low melting point (unsaturated, or polyinsaturated are digested best by aquatic animals.
The criteria used at formulation level are therefore not simple and are not always accessible either: certainly the usual protein tenors in amino-acids are easy to find in tables, but same dose not apply for fatty acids. simple glucids, etc… When there is no data available, the nutritionist must then make out is own tables or formulate judgements on such and such a raw material. according to the more or less subjective knowledge at is disposal.
4. A SUMMERY ON THE ANTINUTRITIONAL AND TOXIC SUBSTANCES FOUND PRESENT IN FOOD
(Table I)
4.1. Distribution of these substances
On the whole, animal raw materials are poor in antinutritional factors, in spit of assertions made by supporters of vegetarian feeding. The principal examples known, are the presence of the chelating factor, biotin and of an antiproteasic activity in the white of a raw egg, along with the presence of a thiaminase in raw fish especially.
Certainly, animal meal (from blood, meat, fish…) can sometimes be considerably toxic, when it or not properly stored or when the products employed are they themselves damaged before the food is manufactured: but this toxicity caused by bacterial toxins is not part of the main characteristics of this food. The same applies for products which have been submitted to badly supervised technological treatments especially, the use of fatty acids peroxides which have a renown noxious characteristic, along with the presence of toxic preservatives (formol in fish meal).
Plants of the contrary contain, quite often, substances which can limit, either the appetence (unpalable substances) or the utilization of the nutriments by the animal (antinutritional substances), or interfere with its physiological functions (toxic poisonous substances). The letter have often no role in the physiology of the plant and appears as a simple means of defense of the plant against the animal: these means, are generally more dissuasive (toxic but not mortal) than deadly (real poisons). The principal families of this immence arsenal areas following: complex membranous glucids, polyphenolic substances, saponins, and other glucosids, alkaloids, enzymatic inhibitors, lectins. Other compounds can have an unfavoubrale and even a real toxic effect: phytic acid, fermentable glucids, “abnormal”fatty acids, amino-acids containing selenium, etc…
Let us now give a brief summery on each one.
4.2. Complex membranous glucids
These are widespead compounds in all vegetable diets and have an unquestionable physiological function on the plant: They are the basic structures of the vegetable cell wall; they can therefore from the constituant matter of whole tissues such as textile fiber cellulose or wood lignin.
These compounds, being very diversified, are always formed by polymerizaiton of simple sugars (glucose, fructose, galactose, pentoses, etc…). They differ from other compounds by the presence of numerous phenolic functions. These compounds form distinct groups in terrestrial superior plants (cellulose, pentosans, other hemicelluloses, pectins, lignin) and in algae algin, carragheen, agar agar. The precise dose of these diverse compounds being difficult and long to carry out, the WEENDE method is often employed instead, for the cellulose and raw fibre, which furnishes a rough and often debatable estimate of all these compounds. The VAN SOEST method which distinguishes hemicellulose and cellulose on one hand, lignin on the other, should be more suitable but is still not adapted to all the products.
Let us recall that if superior animals contain no compounds of this type, we can find in crustaceans, insects and some other invertebrates, a compound similar to cellose: chitin.
Purified and added to diets in moderate doses, these compounds have often no effect at all or a benefical one (the ballest being favourable for the functioning of the digestive tract). In a natural state in the vegetable tissues, even when minced or mixed, they always limit the digestion of nutriments, first, of their own tissue and then of other food compounds. The same applies for certain polysaccharides which are added in high doses to fish food, such as alginates or guar gel.
The norms vary according to the species (herbivora are more tolerant due to the particular anatomy of their digestive tract and the bacterial flora which they accomodate) and these are not well known for fish. In practice, as the food contains less than 5 % of raw cellulose, it rarely creates nutritional problems; at around 10 to 15 %, they must be incorporated with care into the diets of non herbivorous fish, at more the 20 % they must on general be rejected. In the case of herbivorous species such as mullet, supplementary research is required.
It must be remarked that certain invertebrates, in particular crustaceans, posses enzyms which hydrolize cellulose and chitin. The fresh water shrimp Macrobrachium rosenbergii in particular, seems capable of benefiting from high doses of food cellulose which for this animal is a real source of nutriments.
4.3. The phenolic compounds
These are very diverse compounds, which are widespread in vegetation. Although deriving from a same basic molecule (5 hydroquinic acid) they can have very different formulas and degrees of polymerization. There exist compounds with small molecules (coumaric acids, hydrolizable tannis) while other have real macromolecules (condensed tannins). Lignins, complex macromolecules are indirectly linked to this group. This complexity make global dosing difficult or even impossible: The diverse colourmetric methods proposed give very conflicting results. Tannins which are classed by nutritionists as the most important group of polyphenols do not form a well defined entity. They are more or less polymerized molecules which tan leather (from where they got their name), and precipitate gelatine and other proteins.
Phenols and polyphéenols play an important physiological role for plants, they are some times linked to the colour of teguments and flowers, but their role is often obscur, apart from their machanisms of defense. Ingested by the animal, they have almost systematically a negative effect. Their role can reach interference stage, with the reproduction function of female mammels (oestrogenic role of the inoflavin by-products). Generally they reduce appetite due to their sourness, and have and astringent power on the digestive tract, they precipitate enzymatic proteins which decreases therefore digestibillity. They can be absorbed, and release a machanism of intoxication which will modify for example the methionin and cholin requirements. They can also influence the intestinal flora (superior vertebrates). For example, doses of around 0. 5 % of tannic acid will suffice to to reduce the growth of animals and cause mortalities in poultry. A decrease in the toxicity of tannins can be obtained by supplemeting diets with methyl group donors. Tannins can also become are less denatured due to heat, lime, etc…, but the best means of elimination remains, the selections of varieties which are poor in or completely devoid of these polyphenols (sorghum and leguminosae without tannins).
Let us remark that the study of these molecules is not well developed, and that a very limited data is available on the raw material tenorsin tannins or other phenols.
4.4. Saponins and other glucosides, alkaloids
Glucosides are molecules containing one simple are very little polymerized glucide which is linked to another molecule of varied nature called aglycone. Certain glucosides possess very active and even severe toxic pharmaceutic properties.
Glucosides, whose aglycone is either steroide or triterpenic are called saponines due to their hydrophyilo-hydrophobic properties (affinity with water and lipids) which are similar to those are soap. They are found present in a great member of plants. Saponine doses are measured in specialized laboratories which carry out chemical methods and tests on insects. Saponines are toxic for superior vertebrates, principally because of their sequestrum properties with regards to cholesterol; they are even more toxic for invertibrates, which do not synthesize holesterol, and also for fish. For the later, it seems that the toxicity of saponine is derived from its foaming capacity which perturbs the functioning of their gills.
Another example of glucosides of great practical importance is that of colza thioglucosides (vinylthio-oxazolidon), which have antagonizing effects on the thyroid hormones. These compounds can be inactived by thermic treatment. We shall also remark the presence of gossypol in the cotton seed, and which seems to play a multiple role: decrease in the digestion of proteins, slowing down of the proteic synthesis, anemia weaking power.
The aglycone of glucosides can consist in an alkaloid molecule, a group of compounds, characterized like glucosides themselves by the very remarkable properties at pharamaceutical level, which ranges from bitterness to acute toxicity. The solanine found in the potato is an example of a glucoside, with the alkaloid of little activity and found present is small quantities in common foostuff. On general, the presence alone of alkaloid in a vegetable makes it inedible. However, there exist certain cases where the alkaloid rich raw materials can be used after the correct treatment (bitter lupins) has be carried out.
Alkaloids are after very resistant to heat and difficult to destroy, but there also exists, as in the case saponines, important variations from one sort to the next, within the same species. The acquisition of different lupins without alkaloids in not new; the production of colza, poor in thioglucosides and lucerne containing hardly any saponine, constitute another improvement stage of the food values of fodder.
4.5. Antitrypsic and other antienzym factors
These are compounds of proteic or peptidic nature which are very common in the seeds of certain plants, especially leguminosae, such as the soya bean. These factors inhibit the action of trypsin which also casues a hypersecretion of this enzym by the pancreas, which becomes hypertrophied. This effect is more or less remarkable depending on the dose ingested. Its effect is negligible at feeble doses but corresponds to proteic malnutrition at high doses and can cause the apparaition of cancer.
Most of the antitrypsic factors are thermolabile (this is the general case for leguminosae) and the appropriate thermic treatment will suffice so as to bring them down to an acceptable level.
In the same way, as certain vegetable proteins inhibit trypsin, others inhibit trypsin, others amylases. These last factors have been remarked especially in cereals. Their action however much more moderated, and due to this fact, they are of less importance.
4.6 Lectines
Lectines are like antitrypsines, proteic molecules, found commonly in vegetable diets. They have a curious characteristic of sticking onto the glucidic residue of the membranes of certain animal cells, causing their death (ex. hemagglutinins settle on erythrocytes).
Lectines can be violent poisons (ricin aced lectines) or cause simple reductions in the digestive functioning through their destructive action on the intestinal cells.
Due to their proteic nature, lectines are inactivated by heat, but some of them are quite resistant and are a real danger to man and animal (seeds of certain bean species).
4.7. Diverse compounds
The most classical example of antinutriments is certainly phytic acid or hexaphosphoric inositol acid. This molecule, found commonly in the seeds and tubers, has as role the stocking of phosphore and metals in plants. It has multiple chemical properties (antioxidant and complexing especially) which give it a particular role in the digestive tube of animals: to begin, it can complex calcium and other metals, such as zinc copper, manganese, thus making them scarce. It can also from complexes with proteins or starch which makes them less digestible. It also constitutes a source of phosphorus, which is not greatly employed, as the animals have no phytase, and only a part of the phytic phosphorus is absorbed after hydrolysis by the bacterial enzyms.
Let us remark that for reasons which are still obscur, phytic acid is not toxic for japanese shrimp but its nocivity for other fresh water fish has been clearly established.
Let us mention some other elements or compounds, found present in plants, and which are likely to cause disorders in animals which consume them; erucic acid (unsaturated C 22 fatty acid), amino acid which contains selenium, instead of sulphur, oxalic acid, diverse antithyroids, toxic amino acids, enzyms such as the ascorbase of cucurbitacae seeds and the urease of soya, etc…
5. NATURAL AND ARTIFICIAL CONTAMINANTS
We have already stated the bacterial toxins which can confer to animal products, an acute toxicity: similar properties can be found in vegetable raw material which are atteched by microscopic fungus (mildew). This toxicity, which has been known for a long time, was attributed to substances which are being progressively identified, and whose activity is extraordinary (aflatoxin for example is 100 to 1000 times more cancerigenic than the most powerful synthetic oncogenes known). Although present at trace stage, these substances can now, be measured in a certain number of laboratories. They are frequently found in raw materials which are not properly stocked and especially in those which have been stored in a hot humid atmosphere. Let us remark that the presence of a species of fungi secreiting a mycotoxin is no proof of the presence of the latter. Save exception (destruction of aflatoxin by ammonic vapors) it is not possible to eliminate these toxins but only to separate damaged products.
Let us only recall to mind briefly the compounds commonly employed by man which are likely to contaminate animal foodstuff: weedkillers, fungicides, and moreover organo-chlorinated or organophosphorated insecticides, etc…The most active among these can be easily dosed. Heavy metals are also very toxic, in particular zinc and copper (which are necessary in feeble does) lead cadmimum and mercury especially. It must be remarked that they can also originate naturally. We shall only briefly recall to mind the possibility of the transmission of pathogenic germs by foodstuff: this is an extremely rare case.
6. QUALITY CONTROLS (cf. Tables 2 and 3)
If we are only concerned by the verification of the nutriments tenors, two attitudes can be adopted by the manufactures; either the soul use of raw materials which have been correctly analysed or the complete trust in the mean composition of the product.
The second attitude is still more widespread, especially for manufacturers who have not a sufficient means for analysis at disposal This method is also adopted by modern and well managed enterprises where at least certain raw materials have been verified, it is more economic to use rapidly a stock of raw materials which have be bought in confidence, while leaving a security margin in the formulation rather than to immobilize, analyse and to more or less adjust the formula to the real composition.
But this attitude, which has proved itself valid for products of very constant quality (cereals, soya cake) usual fatty matters is not acceptable for vegetable by-products which can have the rate of cellulose vary from 1 to 2, for animal meals whose ash tenor can not be guaranted, for vegetable species of unknown variety, which can contain one or more toxic substances. The resort to more or less numerous analyses has become more and more necessary as the foodstuff can vary naturally, thus it is badly know and adulterations have been suspected (fraud). But due to the number of analyses required theoretically, it is difficult to perform all of them. Due to their cost, we must therefore limit ourselves to the strict minimum necessary. It is also important to know how to interpretate them and especially to keep in mind the remaining unknowns. The WEENDE method of analysis remains valid although its limits have been underline more than once (graph 1)> It is therefore important to complete by a more detailed analysis: amino acids, fatty acids starch and sugar (Table 4) etc... . However, detailed these analyses may be, they only give a rough idea of the elements present, and not the digestible or available food. In practice, the measuring of certain anti-nutritional factors or of certain indirect criteria (red phenol test on soya) can however give indications on the digestibility of nutriments. Chemical analysis is not the only method of control employed:Bacteriological or fungal research can also be carried out, along with the identification of raw materials under microscope and the use of market value criteria (density, aspect of cereals, etc...). Table 5 shows diverse criteria of the market value which is more or less employed.
7. THE PRINCIPAL RAW MATERIALS (Brief summary)
7.1. Animal raw materials
Although they represent a very feeble part of the food for terrestrial animals, raw materials of animal origin nearly always represent more than 50% of the food for aquatic animals. This is due to two reasons: on one hand, aquatic animals (poikilothermic) require high quantities of protein when expressed in percentages of the total ration, on the other hand “carnivora” are much more numerous than “herbivora” among the fish species that man has chosen for aquaculture.
It was rapidly discovered that for nutriment inputs of around equal amounts, the carnivora species showed better growth when their diet basis contained animal meal than when vegetable products were employed. The reasons of this superioritry are not always evident: It is true that thier digestibility is always higher and the profile of their amino acids is generally quite similar to that of the ideal protein for the animal. But other factors can also play a capital part: appetence, richness in group A vitamins, the presence of “unknown growth factors” along with, for products of marine origin, the presence of essential fatty acids (longchain polyinsaturated fatty acids).
These products have also the advantage of being devoid of cellulosic type compounds along with the presence of nearly all the antinutritional factors, but they also entail notory disadvantages:high risk of bacterial contamination; limited time of conservation, poor binders (with the exception of blood meal). Amongst the specific disadvantages of the products, let us point out the excess calcium of bed quality in meat or fish meal, the excess of saturated fatty acids in meatmeal, the risk of peroxidation of unsaturated fatty acids of fish meal, the unbalance of certain proteins (blood and especially feather), etc…
The most useful controls, apart from those for proteins, lipids and ash, are the microscopic examination, the measuring of the peroxidation of fats, available lysin, heavy metals, eventually the histamin tenor. Adulteration of these products is feasible with urea or feather meal, etc...
7.2. Vegetable products (of Table 6, 7, 8)
Very numerous less adapted to the requirements of marine fish (save some exceptions such as mullet and vegetarian shrimp), they can however be very useful:
- as sources of digestible glucides, they permit substantial saving of protein and even lipids,
- as sources of digestible or indigestible polysaccharides, they can be great binders (wheat and wheat by-products, purified starch, pregelatinzed or processed starches, guar, gum, alginates, etc…
Some of them are excellent sources of group B vitamins which do not leach easily as they are enclosed in vegetable cells (By-products of rice and wheat)
- Being generally cheaper than animal meals, they often permit to out down greatly on the production coasts.
Nevertheless, these products are genrally less appetizing to fish than the preceding raw materials, their tenors in cellulosic products must be carefully surveyed along with the numerous antinutritional factors that they contain or may contain if not properly treated. From this viewpoint, it is essential to take the products one by one into consideration, by referring to the individual composition while not forgetting that all antinutritional factors are not completely known, especially as to concern inhabitual raw materials, and that their effect on fish is even less known. Certain vegetable products, especially those from tropical countries are also likely to contain very dangerous fungal toxins. The presence of pesticide residue is also a common occurence in these raw materials.
In comparison to unprocessed products, such as cereals and proteagineous leguminosae, industrial by-products are often standardized and their tenor in antinutritional factors is more often lowered. It is however necessary to verify the composition (cellulose) and the efficiency of the technological treatments carried out.
Table 7 shows the characteristics of some inhabitual Mediterranean products.
7.3. Microorganic products
Although these raw materials are scares, they are relatively well employed in fishfeeding. The most re nown are yeasts, rich in group B vitamins, but they also contain other products (bacterial protein PRUTEEN).
The supply of growth factors and of antinutritional factors is still quite unknown for this food.
7.4. Other products
Salts (sources of essential minerals), pure amino-acids, binders, carotenoids also make up raw materials of which can be taken into account in this report.
CONCLUSION
Raw materials, vast basic source of nutriments, from which the food manufacturer can make a precise and strict choice (if he only takes nutriments into account), are in reality a series of complex products. Their systematic control is far from being accessible for the manufacturer as it is very expensive, antinutritional factors are not all known, their effect on fish is even less known. Therefore, for the present, it is advisable for fish rearers to choose only sure products, avoiding any surprises occurring at either analysis or employment levels. The technical and economical progress expected will only be feasible if we enlarge progressively the gamme of raw materials and for this, much theoretic and applied research, many initiatives and empiric tests, are necessary.
TABLE 1: PRINCIPAL ANTINUTRITIONAL FACTORS OF SOME LEGUMINUSAE
(Non restrictive list)
| Scientific Name (Latin) | Vernacular Name | Tan., Polyphen. | Alc. Gluc., - Sap. | Inhib. Tryps. | Lect. | Ac. Phyt. | Div. and Rq | |
| French | English | |||||||
| Arachio hyrdges | Arachide | Puanut | + | ++ | Frequent | |||
| Cajanes cajan | Pois d'Angole | Pigeun pes | + | + | Aflatoxin | |||
| Canavalia meifornie | Pois sabre | Jack bean | ++ | |||||
| Coratonis eillius | Caroube | Carob | ++ | In pods | ||||
| Cicer arlation (Lane asculmea) | Pois chiche | Chick pea | ± | + | + | + | ||
| Delichoe lablab | Dolique | Myscinth bean | ++ | + | + | |||
| Ervue Lane | Lentille | Lentil | ++ | + | + | Thersolabile | ||
| Glyeine max | Soys, sojs | Suybean | + | + | ++ | Factors | ||
| Lathyrus eativus | Gesea | Chickling vetche | ++ | + | Difficult factors to be destroyed | |||
| Lathyrus sp. | Gesses | Chickling vetches | ++ | (+) | By heat | |||
| Levesane glauco | Ipil ipil | Ipil-ipil Lead-tree | ++ | In leaves | ||||
| Lupiane altue | Lupin blanc | White lupin (e) | - | ±, ++ | - | |||
| L. angustifolius. L. sp. | Lupin bleu, ... | Blue lupin (e) | - | ±, ++ | - | Varieties without | ||
| Medicago eativa | Luzerne | Lucerne, alfalfa | ±, ++ | alkaloids | ||||
| Phaeoclus vulgaris | Naricot (ord.) | Bean, kidney bean navy bean | ± | ± | ±, ++ | ++ | ±, ++ | Very thernelabile factors |
| Phaecolus linatus | Naricot de Lims Pois du Cap | Lias bean | + | ++ | + | + | ||
| Phaecolus op. | Naricots div. | Beans | (+) | ? | (++) | (++) | (+) | |
| Plaun eativus | Pois (de jardin) | (Garden) pea | ± | ± | + | + | ||
| P. avense | Pois fourrage | Field pea, | + | ± | + | |||
| Trigonella fomusroecun | Fenugrer | Fenugreek | ++ | |||||
| Vicia fabe | Fèe, fèverole | Field bean, fabs bean, etc... | ± | ± | + | Varieties without tannin | ||
| Victi sp. | Vesces | Vetches | (++ ?) | (++ ?) | {+ ?) | (+ ?) | (++ ?) | Not well known |
| Vigna mungo = Fhsecolus | Haricut mungo | Mung bean, black gram | +, ++ | + | ++ | |||
| Vigna radiats = Phageoius iureue | Amburique | Green gram | ±, ++ | + | + | |||
| Vigna uncicuiata = Vigna sinemsis | Doligur mungette nicbe, yeus nuirs | Cuv pea. black vyes | ± | ±, ++ | + | |||
TABLE 2: AN EXAMPLE OF THE CONTROL OF RAW MATERIALS FOR FISH FOOD
(BENAYAS BEVIA, 1986)
A. CHEMICAL CONTROL
- Proteins
Digestible protein(pepsic digestion in vitro)
Amino-acids
Available lysine
- Lipids
Linoleic and linolenic essential fatty acids
Acidity of fatty material
Peroxide index
- Minerals
Tenor in oligo-elements = Fe, Cu, Zn, Mn, Co
Tenor in toxic element = Pb, Hg and F
Insoluble HCL
Sodium chloride
- Glucids
Monosaccharides: Glucose, fructose
Disaccharides: saccharose (= sucrose)
Starches
- Antinutritional elements
Mycotoxins: aflatoxins, ochratoxins, zaralenone
Nitrites and nitrates
Gossypol, etc…
B. BACTERIAL CONTROL
- Lacteous products
Genus Salmonella
Species Escherichia coli
Geneus Staphyllococcus
- Animal meals
Genus Salmonella
Species Escherichia coli
Genus Staphyllococcus
Mesophile aerobic bacteria
Coliforms
Fungi and yeasts
- Research of residues
Insecticides
Rodenticides
Pesticides (sic)
TABLE 3 - An example of control analysis on raw material for fish food
(BENAYAS BEVIA, 1986)
| F Fish | F Meat | F Blood | F Feather | Vegetable products (in general) | cakes | Mineral substances | Vitamins | Fatty matter | |
| H2O | + | + | + | + | + | + | + | + | + |
| Prot.brutes (N × 6.25) | + | + | + | + | + | + | + | ||
| Prot.dig. (in vitra) | + | + | + | + | |||||
| Lysino disponible | + | + | + | + | |||||
| A.A. soufrè | + | ||||||||
| N non pracoique | + | ||||||||
| Lipides brute | + | ||||||||
| Aciditè des lipides | + | + | |||||||
| Indice de pèroxyde | + | + | |||||||
| Ac.gras. | + | ||||||||
| Sterols | + | ||||||||
| Point Fusion | + | ||||||||
| Anvioxydancs at autres conservateurs | + | + | |||||||
| Cellulose brute | + | + | + | ||||||
| Glucides | + | ||||||||
| Cendres | + | + | + | ||||||
| Nacl | + | ||||||||
| Na | + | ||||||||
| Insoluble Hcl | + | + | |||||||
| P | + | ||||||||
| Fe | + | ||||||||
| Cu | + | ||||||||
| F | + | ||||||||
| Fb | + | ||||||||
| Cations correspondancs: No-2 No-3 | * | ||||||||
| Aflacoxinos | + | + | |||||||
| Rèeid. insoeticides | + | ||||||||
| Vitamines | + | ||||||||
| Salmonelles | + | + | + |
An exemple of the norms retained for the control of fish food
(BENAYAS BEVIA, 1986)
| Optimum | Maximum | Remark | ||
| NaCl | 1,2% | |||
| Ca | 2,2 – 1,8 | 2,2% | Risk of water pollution | |
| P | 1,5 – 0.9 | 1,5% | ||
| Fe | 1250 ppm | |||
| Zn | 250 ppm | |||
| Mn | 250 ppm | |||
| Cu | 50 ppm | |||
| Ca | 10 ppm | |||
| F | 15 ppm | |||
| Pb | 1 ppm | |||
| Hg | 1 ppm | |||
| Digestibilitè pepsique des protéeins | 80 – 90 | 80 | ||
| Lysine * | D 3,1 - C 2,8 | |||
| Methionie + cystine * | 13 – 1.7 | |||
| Aflatoxine | 5 ppb | |||
| NO-2 et NO-3 | 5 ppm | |||
| Gossypol | 20 ppm | |||
| Excellent | Optimal | Normal | Abnormal | |
| Acidity of the fatty matter (%) ** | 8 | 15 | 15 – 25 | 30 |
| Peroxide index (meq O2 kg-1 | 8 | 12 | 20 | |
* Trout food - D: demarrage, C: growth
TABLE 4 : PRINCIPAL ANALYSISES COMPLETING THE ANALYSIS BY WEENDE
| Dosed Elements | Methods | Remarks | |
| Ash | P | Colorimetry | Usually employed |
| Ca, Na, K, Mg | Spectrophotometry | Only Ca employed | |
| Fe, Cu, Zn, Mn, Co | (atomic absorption) | ||
| Proteins | Amino acids | Liquid phase chromatography, HPLC | Quite usually employed, Use of tables possible |
| Available lysin | Colourimeter | Debatable | |
| Lipids | Lipid categories | Solvant separation | |
| Fatty acids | Gassy phase chromatography | Quite usually employed | |
| Cellulose | Acid detergent extracts | Easy, should be generalized but the method to be adopted to particular cases | |
| Neuter detergent extracts | |||
| Glucids | Starch | Acid hydrolysis Enzymatic methods | Numerous methods only to be chosen in accordance to the nature of the product |
| Glucose | Reducting power Enzymatic methods | ||
| Other sugars | Numerous methods |
TABLE 5 : Different types of criteria for the quality of raw materials
Traditional “Sale Value” (Cereal especially)
- Specific weight
- (Small blender, broken, grains, … ) aspect of the grains
- Colour of the grains
- Odour
- Contamination (mildew, insects)
- Presence of impurities
• Other grains
• Soil, debris
Other biological criteria
- Degree of ripeness
- Varietal purity
Microbiological examinations (animal meal, cakes)
- Bacteria
- Fungi Spores
Microscopic examination of raw materials (grounded or minced products)
- Micrographic analysis
Chemical analysis
- by WEENDE
- Supplementary analysis of the constituants
- Research of Contaminants
- Indirect tests
Biological tests
- Toxicity
- Digestibility
TABLE 6 : PRINCIPAL CEREALS
| Scientific Name | Vernacular name | ||
| French | English | ||
| Triticum aestivum | blé | wheat | Cereal of reference - Antinutritional factor negligeable with the exception of phytic acid. Acid very suitable for fish. |
| Zea mays | maïs | maize(corn) | less protein and certain vitamins more energetic |
| Hordeum sativum | orge | barley | Less digestible and glucids - rich in cellulose and gum - Not well utilized by fish - some tannic products. |
| Avena sativa | avoine | oats | High cellulose content - it has less digestible glucids - much less energetic hardly utilized by fish |
| Oryza sativa | riz | rice | whole cereal (paddy) very rich in cellulose, nethertheless it is employed in aquaculture food. (especially by-product) |
| Sorghum Vulgare | sorgho | milo | A cereal similar to corn by its composition, although more variable - Some varieties are very rich in tannins (and in phytic acid). |
| Triticale x (Triticum x Secale) | triticale | triticale | A new cereal interesting due to its composition |
| Polygonum tataricum P. Fagopyrum | sarrazin | buck wheat | A rather similar composition to that of graminacae, contains a photosensitivizing alkaloid. |
TABLE 7 : PRINCIPAL CAKES
| Scientific name | Vernacular name | ||
| French | English | ||
| Glycine maz | soya | soyabean | Excellent source of protein if well cooked (methionine deficiency) |
| Arachis hypogea | arachide | pea nut | High protein content,but lacking lyaine and methionline - Can present aflatoxins. |
| Sesamum indicium | Sesame | Sesame | Low lysine content - |
| Gossypum sp. | coton | Cotton | Rather high cellulose content - not a good energetic source - Presence ofgossypol |
| Elaeis guineensis | palmiste | High cellulose content - Not a good energetic sources, rather low protein content of average quality - Can present aflatoxins. | |
| Cocos nucifera | Copra | Coconut | |
| Helianthus annuus | tournesol | sunflower | Protein Lacking lysine - Difficulty in bulling this product correctly (excess cellulose) |
| Brassica napus B. Compestris | colza | rapessed | Average protein content of good quality - Rather high cellulose content - Presence of great quantities of glucosides (Vynil - thioxa-zolidones) except when treated or of special varieties. |
TABLE 8 : COMPOSITION OF SOME INHABITUAL RAW MATERIALS WHICH ARE EMPLOYED
IN ANIMAL FEEDING IN MEDITERRANEAN REGIONS
| French | English | Prot.brut | Cell.brut | E.N.A. | Extr.eth. | Min.tot. | |
| Rare Cereals | |||||||
Phalaris canarensis | mils millets | millets panics | 13,0 | 5,8 | 55,8 | 7,4 | 6,6 |
Setaria italica | 10,6 | 4,1 | 58,7 | 10,8 | 3,8 | ||
Panicum miliaceum (décortiqué) | 13,2 | 3,8 | 70.0 | 2,0 | 1,5 | ||
Andropogon durra | 10,3 | 3,5 | 72,4 | 1,6 | 2,0 | ||
| Rare cakes | |||||||
Guizotia abyssinica | niger | niger | 33,1 | 6,5 | 22,2 | 18,6 | 8,8 |
Citrus sp. (graines) | citrus | citrus | 28,3 | 8,0 | 33,0 | 18,0 | 4,0 |
Amygdalus Communis amande | amande | almond | 40,8 | 16,5 | 18,9 | 9,2 | 4,3 |
Orbynia speciosa | babassu | babasou | 24,5 | 0,8 | 40,7 | 18,0 | 6,0 |
Camelin sativa | cameline | dotter seed | 33,0 | 9,7 | 29,1 | 11,2 | 6,5 |
Cannabis sativa | chanvre | hemp seed | 30,5 | 9,8 | 19,2 | 20,5 | 8,8,0 |
Cuoubita sp. (graines) | courge, citrouille | cucurbit | 50,5 | 12,0 | 6,6 | 15,0 | 7,9 |
Paperver sp. | pavot oeilleté | poppy seed | 36,0 | 1,0 | 24,6 | 15,1 | 11,5 |
| Diverse graines | |||||||
Ceratonia siliqua | caroube | carob | 16 | 1,7 | 58,2 | 6,8 | 3,0 |
Castanea sativa (déecortiquée) | chataigne | chest nut | 5,7 | 4,0 | 79,0 | 1,5 | 2,3 |
Quercus sp. | gland | acorn | 6,4 | 4,0 | 69,2 | 4,9 | 2,5 |
| Diverse vegetable products | |||||||
Phoenix dactylifera (pulpe) | datte | dattes | 5,2 | 0,3 | 62,5 | 5,5 | 2,5 |
Laminaria sp. | algues | sea weeds | 9,2 | 1,5 | 58,5 | 6,2 | 15,2 |
| Rare animal products | |||||||
| Bombryx mori | very à soie (chrysalides) | silk worm | 61,6 | 5,6 | 7,6 | 8,0 | 5,2 |
GRAPH № 1: DOSAGE ACCORDING TO THE WEENDE METHOD
| Fresh material | ||
| H2O | ||
| oven 110° | Dry material (1) | Difference (6) |
| Oven 550° | Ash (2) (mineral) | Non azotized extract = glucids “utilizable” |
| N Kjeldahl | N × 6.25 (3) (Raw proteins) | |
| Delipidation | Ether extract (4) (Raw lipids) | |
| Separation of the fibres | Raw cellulose (5) = Raw fibre |
Sources of error
Peroxidation
Oxidation of metal, loss of ponds possible
Factor 6.25 - N non proteic
Extraction adjusted to inferior or superior unit limits
Underestimated
Accumulation of previous errors
No date recording on the chemical nature of glucids
REFERENCE PRINCIPALES
BENAYAS BEVIA D.E., 1986. Control de calidad en alimentos para piscicultura. in Proc. 4th World Congress of Animal Feeding. Madrid 30/06–4/07 1986 IX p. 215–226.
BIRK Y., 1985. Legume sapoins. in Proc. 4th world Congress on Animal Feeding. Madrid 30/06–4/07 1986 IX p. 297–304.
BLUM J.C., 1984. L'alimentation des animaux monogastiques, porc, lapin, volaille.
Ed.INRA Paris.
Traduction : édition anglaise BUTTERWORTMS, London.
édition espagnole Ediciones mundi prensa -Castello 37 - 28001 MADRID
édition italienne ed. Patro - Bologna.
GONTZEA I., FERRANDO R., SUTZESCO P., 1968. Substance antinutritives naturelles des aliments. VIGOT Freres ed. Paris.
KRATZER F.H., VOHRA R., 1985. Phenolic compounds in legumes. inProc.4th World Congress of Animal Feeding. Madrid 30/06–4/07 1986 IX p. 283–292
LEVY-BENSHIMOL A., 1986. Lectin as antinutritional factors in legumes. in Proc. 4th World Congress on Animal feeding. Madrid 30/06–4/07 1986 IX p. 293–296.
LIENER I.E., 1980. Toxic constituents of plant foodstuffs. Academic Press Newyork.
FICCIONI M., 1965. Dizionario delgi alimenti per il bestiame. Edizioni agricols. Bologna (Italia) - Traduction francaise; Dictionnarie des aliments pour les animaux, Adapt. J.HARDOUIN, Officine Grafiche Calderini, Bologna (Italie)
RACKIS J.J., MARQUARFT R.R., 1986. A review of the nutritional properties, content and inactivation of trypsin inhibitors in oilseeds legumes potatoes and cereals. in Proc. 4th World Congress on Animal Feeding. Madrid 30/06–4/07 1986 IX p. 305–317.
THOMPSON L.V., 1986. Phytic acid: chemistry, nutritional effect and removal. in Proc. 4th World Congress on Animal Feeding. Madrid 30/06–4/07 1986 IX p. 319–330.
