antimetabolites antinutritional factors

1.  Antimetabolites
 Anti-nutritional factors.
 Feed additives
Presented by,
Karthika chandran A
Department of Aquatic biology &
Fisheries

2. INTRODUCTION
 Antimetabolites- a substance that interferes with the normal metabolic processes within cells,
typically by combining with enzymes.
 Plants have capacity to synthesize a wide variety of chemical substances that are known to
exert a deleterious effect when ingested by animals – antimetabolites
 These substances are also referred to as antinutritional factors when they are present in feed
stuffs and influence a metabolic pathway when eaten by an organism.

3. Ingestion of antimetabolites will result in death due to inhibition of
growth, decrease in food efficiency pancreatic
hypertrophy,hypoglycaemia ,liver damage and other pathological
conditions.
Most of these substances are heat labile and are easily destroyed by
cooking.

4. The antinutritional factors of plant products can be divided into
4 major groups.
1. PROTEIN –protease inhibitors, haemagglutins.
2. GLYCOSIDES- cyanogen, saponine ,oestrogens
3. PHENOLS –gossypols ,tannins.
4. MISCELLANEOUS- anti mineral, anti vitamins,anti enzyme
,food allergens, microbial plant carcinogens, toxic amino acid

5. ANTI NUTRITIONAL FACTOR
TOXINS OF PLANT ORIGIN
1.PROTEASE INHIBITORS
2.HAEMAGGLUTININS
3.CYANOGENS
4.GOSSYPOLS
5.MIMOSINE
6.PHYTIC ACID
7.GLUCOSINOLATES
8.ALKALOIDS
9.ERUCIC ACID
10.SOYABEAN TRYPSIN INHIBITOR
11.CYCLOPROPENOIC FATTY ACIDS
12. ALPHA AMYLASE INHIBITOR
13.PHYTOESTROGENS

6. 1) PROTEASE INHIBITORS
 They are distributed widely in plants especially among the legumes such as soya bean.
 Protease inhibitors are substances that have the ability to inhibit the proteolytic activity
of certain enzymes.
 Protease inhibitors within a plant ,differing in their molecular weight, structure(amino acid
sequence) and specific action.
 Protease inhibitors basically act by binding with chymotrypsin and trypsin rendering them
inactive.
 Almost all protein inhibitors are heat liable and will be broken when cooked.

7. 2. HAEMAGGLUTININS( lectins)
 Hemagglutinins, also known as lectins, are proteins which cause agglutination of
erythrocytes (red blood cells)
 Hemagglutinins possess a specific affinity for sugar molecules .
 They can bind to free sugar or to sugar residues existing in polysaccharides,
glycoproteins, or glycolipids, in either free or bound form, such as in cell membranes
 Hemagglutinins have been found in a no.of edible plants, most notably in the
legumes including soybean.
3.CYANOGENS
 Occur in many plants in the form of cyanogenitic glucosides
 Found in certain grains, root crops and fruit kernels.
 Cyanogenetic glucosides are hydrolysed by specific glucosidase enzymes, when toxic
hydrogen cyanide (HCN) is liberated.

8. 4.GOSSYPOLS PIGMENTS
 These are found exclusively in the pigment glands ofcotton seed.
 It is reactive and exhibit acidic properties.
 excessive levels of gossypols can result in depressed growth, tissue accumulation,
and histological changes
5.MIMOSINE
 the legume Leucaena leucocephala(ipil-ipil) was recommended as a forage crop for
livestock, and was also considered as suitable for incorporation into fish feed.
 However, it is known that its use as a livestock, feed is limited by the presence of an
unusual aminoacid- mimosine
 Mimosine affect the production of thyroxine and hence the growth of the
organism.

9. 6.PHYTIC ACID
 Phytic acid is an organic molecule related to inositol integral component of plant
feedstuffs
 Plant phosphorus is found in the form of phytic acid,which is a cyclic compound
containing six phosphate groups.
 It is a constituent of all cereal products and oil seed meals such as soybean,
rapeseed, and cotton seed, which are commonly used in salmonid and other fish
diets.
7.GLUCOSINOLATES
 Glucosinolates (thioglucosides) - are responsible for the pungent flavors found in
condiments, horse-raddish, mustard and rapeseed meal.
 Their main biological effect, is to depress the synthesis of thyroid hormones. The
thyroid depressing effect is due to their reducing the incorporation of iodine into the
precursors of thyroxine as well as interfering with its secretion.

10. 8.ALKALOIDS
 Alkaloids comprise a large and diverse group of plant toxins
 The toxicity of alkaloids is usually directly related to their structural complexity
9.ERUCIC ACID
 Erucic acid is a monounsaturated fattyacid and is a normal constituent of rapeseed oil.
 This compound causes lipid accumulation and necrosis of the heart tissue and is toxic to coho
salmon when fed at 3–6% of the diet .
10.SOYABEAN TRYPSIN INHIBITOR
 Soybean meal contains antinutritional compounds, which must be removed or inactivated by
processing before the meal can be used successfully in animal or fish feeds.
 The principal compounds in soybean meal are trypsin inhibitors, which reduce protein digestibility
by binding with the digestive enzyme trypsin in the intestine of the animal.

11. 11.CYCLOPROPENOIC FATTY ACIDS
 The cyclopropene fatty acids (CPFA) are constituent of plants of the order Malvales.
 Cotton seed meal also contain CPFA
 CPFA is found to be carcinogens in rainbow trout.
12. ALPHA AMYLASE INHIBITOR
 Amylase is an intestinal enzyme used to digest carbohydrates.
 Amylase inhibitors are found in wheat and beans.
 The activity of these compounds in digestive tract of fish varies greatly depending
upon their feeding habit
13.PHYTOESTROGENS
 Phytoestrogens are compounds naturally occuring in many plants used for human
and animal food
 The compounds actually responsible for estrogenic activity include the isoflavoxes
and resorcyclic acid lactones.
 Several grains(barley, oats, rice and wheat), soybeans and rape contain these
compounds.

12. TOXINS OF ANIMAL ORIGIN
1.TETRODOTOXIN
2.DINOFLAGELLATE TOXINS
3.HISTAMINE
4.DINOGUNELLIN
5. OXIDIZED FATS

13. 1.TETRODOTOXIN
 About 80 sps of the order tetraodontiformes (the puffer fish or globe fish) produce and
store tetrodotoxin, a complex cyclic compound which is highly toxic to all vertebrate
animals.
2.DINOFLAGELLATE TOXINS
 Several bloom forming organisms are toxic to fish as well as humans and terrestrial animals.
 Gymnodinium brevis cause mortality of large number of fishes
 The toxins get accumulated in the body of fishes.
 The potential for these dinoflagellate toxins to appear in formulated fish diets in rare,
though not imposible.

14. 3.HISTAMINE
 Scombroid fishes may develop high levels of histamine under improper storage condition
 This is due to the action of the bacterium Proteus morganii on the high histidine content of
these fishes.
4.DINOGUNELLIN
 Dinogunellin is a toxic lipoprotein that is produced in the roe of two fish, the northern blenny
and marbled sculpin
 The toxin is not as potent as tetrodotoxin, but it causes diarrhea, nausea, vomiting, epigastric
distress, and liver and spleen necrosis
 The potential for fish toxicity due to dinogunellin in pelleted fish diets is very low.

15. 5.OXIDIZED FATS
 Marine fat oils, high in polyunsaturated fattyacids(PUFA), are very susceptible
to auto oxidation when exposed to atmospheric oxygen.
 The use of oxidized or rancid fish oils in diet preparation, along with the
additional oxidation that occur during diet preparation and storage, result in
the presence of undesirable lipid- derived toxins in diet.
 These toxic components of the diets may affect fish by direct toxicity or
indirectly through vitamin deficiencies caused by vitamin E

16. TOXINS OF MICROBIOLOGICAL ORIGIN
1. AFLATOXINS
 These are the best documented mycotoxins. There are
mainly four compounds named B1, B2, G1, and G2-
Aflatoxin is a potent liver toxin and a carcinogen with aflatoxin B being the most
toxic compound.
2. OTHER MYCOTOXINS
Ochratoxin :Produced by species of the genera Aspergillus and
Penicillium. Ochratoxin A affects the proximal kidney
tubules causing nephropathy. It is teratogenic to many
animals. This-is mostly reported from temperate countries.
Recently rice bran and soya bean meal from tropics also have
been found to contain this toxin

17. FEED ADDITIVES
 What?
 Which?
 Why?

18. FEED ADDITIVES
A feed additive is a food supplement for farm animals that cannot get enough
nutrients from regular meals that the farmers provide and it include vitamins, minerals,
aminoacids,fatty acid.
Feed additives are non-nutritive ingredients that are included in feed formulation.
Feed additives are necessary to stabilize feeds to prevent deterioration during
storage or to improve fish health and nutrition quality.
Feed additives include aminoacid (synthetic),vitamins,hormones,carotenoid
supplements, drugs and antibiotics, antifungals, antioxidants, fiber, flavoring and
water,presevatives , chemoattractants etc,

19. FEED ADDITIVES
12.Water
1. AMINOACIDS
6. Pigments
5.BINDERS
4.ENZYMES
3.HORMONES
2. VITAMINS
7. Chemotherapeutants
8. .ANTIOXIDANTS
15. Preservatives
9.Probiotics
11.FIBER
10.Chemoattra
ctants 13. Flavorings
and Palatability
Enhancers
14.Antimicrobial
agents

20. 1.AMINOACIDS (SYNTHETIC)
 L – lysine and DL – methionine are common synthetic aminoacids.
Used as chemoattractancts as well as to supplement deficiencies in a compound food.
2. VITAMINS
Vitamins are used to supplement for deficiencies in the ingredients of compounded feeds.
They have also been shown to provide additional protection against lipid oxidation ,
enhancing its storage life.
FEED ADDITIVES

21. . Hormones
FEED ADDITIVES
3.HORMONES
 Some feed ingredients contain anabolic steroids and phytoestrogen compound that mimic
the activity of estrogen.
 Hormones are used to influence fish growth rates, sexual development and
osmoregulation.
 Anabolic steroids, thyroid hormones, pituitary growth hormones and insulin have growth
promoting effects.
 Hormones are added directly to fish diets to cause sterility or sex reversal.

22. FEED ADDITIVES
4.ENZYMES
 Increased growth, improved nutrient utilization, and pollution reduction are all
reasons for adding enzymes to formulated feeds.
 The supplemented enzymes seemed to initiate the metabolic process in the digestive
system.
 Phytase is an enzyme commonly used in formulated feed
5.BINDERS
 Binders are incorporated into fish feeds to improve stability in water, increase pellet
firmness, and reduce the amount of fines produced during processing and handling.
 Among the most widely used binders are sodium and calcium bentonites,
lignosulfonates, hemicellulose, carboxymethylcellulose, alginate, etc.

23. FEED ADDITIVES
6.Pigments
 Many plants and animals contain a variety of natural pigments that impart
yellow, orange, and red colors to the flesh, skin, and eggs of fish.
 Xanthophylls and carotenoids are the most important classes of pigments for fish and
crustaceans.
 Canthaxanthin and astaxanthin add color to flesh and eggs.
 Salmon and red sea bream do not have the ability to convert xanthophylls to
carotenoids, and there for must receive these pigments in there diets.
7.Chemotherapeutants
 A wide range of antibiotics are used for therapeutic purposes in livestock production
 Therputants are added to fish feed to treat, cure, mitigate, or prevent disease
 Sulfamethazine, terramycin (oxytetracyclin) and furox are commonly used for this
purpose
 erythromycin and Azithromycin used for the treatment of kidney diseases in captive
breeding salmons, but are not allowed in normal production.

24. FEED ADDITIVES
8.ANTIOXIDANTS
 Antioxidants are commonly used in fish feeds that contain a high concentration
of polyenic fatty acids to prevent the oxidation of lipids
 Oxidative rancidity, or lipid peroxidation, affects the nutritional value of lipids,
oxidation sensitive vitamins, and other feed components
 Natural tocopherols (vitamin E) have antioxidant activity; however, synthetic
vitamin E is usually supplied in the diet in ester form,
 Commercially available antioxidant –BHT (butylated hydroxytoluene),BHA-
(butylated hydroxyanisole) & ethoxyquin
9.Probiotics
 Probiotics may be a single species of microorganisms or a mixture of species.
 Probiotics are live, microbial feed supplements usually bacteria to enhance fish
growth by affecting the microbialflora population in the gut of the animal.

25. 10.Chemoattractants
 Chemoattractants are synthetic chemicals or natural ingredients containing chemicals, such
as free aminoacids, which elicit feeding responses.
 Generally, extractive compounds in muscle of molluscs and crustacea are common flavour
attractance.
11.FIBER
 Fiber refers to indigestible plant matter such as cellulose, hemicellulose, lignin, pentosans,
and other complex carbohydrates found in feedstuffs. These components are indigestible
unless bacterial action occurs within the digestive tract.
 Fiber provides physical bulk to the feed. Cellulose and hemicellulose have been used as
diluents and binders in experimental fish diets

26. 12.Water
 The water content of feeds ranges from 6 – 10 for dry – compressed or extruded pellets to 65 – 70% for
high – moisture, wet pellets.
 Some fish species accept moist feeds more readily than dry feeds, particularly pacific salmon fry and
large – mouth bass.
13. Flavorings and Palatability Enhancers
 Flavorings are common feed additives used for increasing the feed acceptance of cultured species.
 Extracts of crustaceans such as krill, and certain amino acids may increase appetite in fry and
crustaceans.
14.Antimicrobial agents
 Used in the feed industry to inhibit fungal or microbial growth
 Benzoates and parabens and propionate, which are effective against bacteria, fungi and yeast.
15. Preservatives
 Preservatives are added to feed to control the rate of deterioration, particularly from fungal attack.
 Sodium or potassium salts of propionic, benzoic or sorbic acid are used as preservatives.

27. CONCLUSION
 Antimetabolites is a chemical that inhibit the use of a metabolite.
 The presence of antimetabolites can have toxic effects on cells.
 Anti metabolites are also called anti nutritional factors ,when they are present in food
stuff.
 Protease inhibitor,haemagglutinins,cyanogens,gossypols are some of the antimetabolites.
 Feed additives is a food supplement that are non-nutritive ingredients which are included
in feed formulation.
 Feed additives include vitamin,aminoacid ,preservatives, essential fatty acid etc

28. THANK YOU