By Dr. Hussain Ahmad

1. Anti-nutritional factors/
secondary metabolism
Dr Hussain Ahmad Qadri

2. • Chemicals which either by themselves or
through their metabolic products, interfere
with food utilization
• Reduce the absorption of nutrients (macro
and micronutrients)
• Cause growth inhibition
• Affect the health and production of animals

3. • However, some anti nutrients may exert
beneficial health effects relying on their low
concentration, chemical structure, time of
exposure and interaction with other dietary
components
• Phytate, lectins, tannins, amylase inhibitors,
protease inhibitors, goitrogens , oxalates and
saponins
• To reduce the blood glucose
• The plasma cholesterol and triglycerides
• To reduce cancer risks

4. General characteristics
• Found in virtually all plants to some degree
• Defensive role
• Bitter
• Colors
• Poisonous
• Odor
• Immunosuppressive

5. Protease Inhibitors(PIs)
• Sources : seeds of most legumes and cereals
• Effects
1. Inhibit the activity of proteolytic enzymes (Trypsin
and chymotrypsin) within the gastrointestinal tract,
decreasing protein digestibility.
2.Growth retardation and Pancreatic hypertrophy
3. Damage the connections between the enterocytes
of SI (Leaky gut)
• Heat processing
Protein nature denatured by heat processing
(121°C/15min).

6. PHYTATE/ INOSITOL HEXAKISPHOSPHATE (INSP6)
• Source: In mature seeds. Comprising 0.5 to 5
percent (w/w)
• Effect: Phytate bind (chelating) divalent and
trivalent mineral ions such as Zn2+, Fe2+/3+, Ca2+,
Mg2+,Mn2+, and Cu2+ to form complex phytate
cause low absorption of minerals from small
intestine.

7. Inositol:inactive alcohol that is a component of the vitamin B complex

8. Tannins (Phenolic Compound)
• A yellowish or brownish bitter-tasting plant
polyphenolic compound.
• Source: Cotton seed , canola and sorghum
• Two types a)hydrolysable b)condensed (mainly cause
problems)
• Effect: Decrease feed intake, decrease protein
digestibility by either making protein partially
unavailable or inhibiting digestive enzymes and
increasing fecal nitrogen , decrease growth rate

9. Tannins

10. Saponins (Glycosides)
• ‘Saponin’ derived from Latin word sapo means ‘soap’,
combination of polar and non-polar structural
elements in their molecules explains their soap-like
behavior in aqueous solutions.
• Source: soya bean meal, sunflower meal and guar.
• Effects: toxic, reduce food intake due to bitterness
throat-irritating activity , strong hemolytic activity,
reduce bioavailability of nutrients, affects protein
digestibility by inhibiting various digestive enzymes
such as trypsin and chymotrypsin.

11. Oxalates
• Salt formed from oxalic acid known as Oxalates
• Strong bonds formed between oxalic acid, and
various minerals such as Ca, Mg ,Na , and K such
as Na and K, are soluble, whereas calcium oxalate
salts are basically insoluble.
• Source: Vegetable protein source
• Effects: hypocalcaemia, Tatany , and death due to
combination with calcium also effect kidney and
renal failure.
• Detoxification: cations used with diet.

12. Mycotoxins
• Secondary metabolites of fungi
• Source: Aflatoxins, produced by Aspergillus flavus and
Aspergillus parasiticus.
Growth Ideal conditions moisture levels in feed (above
14%), temperature (above 27° C), humidity (above
62%),poor aeration.
• Prevention: Store feeds in a cool and dry area.
Inspect regularly
• Types: Aflatoxins appear fluorescent under U.V. light,
named aflatoxins B ( blue color) or aflatoxins G ( green
color) Aflatoxin B1 most potent one.
• Effects: Carcinogenic, Aflatoxicosis pale lungs , impaired
blood clotting , depress immune system by destroying
essential nutrients (e.g., vitamins A & C, and thiamine)

15. Lectins (Hem agglutinins)
• Ch2O binding proteins, bind glycoproteins and sugar
from the cell membranes.
• Proteins that agglutinate red blood cells with known
sugar specificity are referred to as “lectins”, name
“hem agglutinins” is used when sugar specificity is
unknown.
• Source: Soybean, Guar
• Effects: severe intestinal damage, disrupting
digestion, bind to erythrocytes causing hem
agglutination and anemia. Decrease cell to cell
interaction.

16. Alkaloids
• Heterocyclic nitrogenous compounds ,
basically salts of plant acids such as oxalic,
malic, tartaric or citric acid , formed as
metabolic by products, insects and herbivores
repulsed by their toxicity and bitter taste
• Source: 15 to 20% of all vascular plants
• Effects: Disruption of cell membrane in GIT,
rapid heart rate, paralysis, neurological
disorders

17. Gossypol (polyphenolic)
• Source: present in pigment glands of plants of
genus Gossypium (e.g.,cottonseed)
• Toxic in free form but processing cottonseed with
heat free gossypol bound to proteins (reactive
epsilon amino group of lysine) ,level can be
reduced by 50-99% although final protein
bioavailability is consequently reduced
• Solution: select varieties free of pigment glands.
• Effects: problems to reproductive system by
affecting reproductive tissues or pituitary and
gonadol hormone secretion, impaired protein
digestibility, reduced growth.

18. Cyanogenic Glycosides
• General function in plants dependent on activation
by b-glucosidases to release toxic volatile HCN,
ketones or aldehydes to fend off herbivore and
pathogen attack
• Source: cereals, root tubers, legumes and oilseeds
• Effect: block respiratory chain reaction, cellular
hypoxia occurred.
• Detoxification: heat-stable, soaking three days at
30°C and sun drying for another two days or
incubating at 30 °C for 18 hours followed by steam
heat to evaporate HCN are efficient treatments.

19. Erucic acid (fatty acid)
• Erucic acid (cis-13-docosenoic acid) is a 22-
carbon monounsaturated fatty acid.
• Source: rapeseed and mustard oils
• Effects: reduced growth, increased mortality,
and histopathology of skin, kidney.
• Detoxification: removed from seed by oil
extraction.

20. Lathyrogens
• Sources: plants of genus Lathyrus such
as grass pea
• Effects: lathyrism (skeletal lesions, retarded
sexual development and paralysis)
• Detoxification: removed by cooking in water
(100°C) and draining off excess water.
Soaking dehusked seeds overnight followed by
steaming for 30 minutes.

21. Anti-enzymes
• Group of compounds having an anti-enzymatic
activity such as the amylase inhibitor, the
invertase inhibitor, and the arginase inhibitor
(derivative of chlorogenic acid)
• Source: cereal, root tubers, legumes and
oilseeds.

22. Anti-vitamin factors
• Group of compounds having an anti-vitamin activity
- Anti-vitamin A destroys carotene
- Anti-vitamin D interferes with calcium and phosphorus
absorption
- Anti-vitamin E causes liver necrosis and muscular
dystrophy
- Anti-thiamine factor (thiaminase) causes deficiencies in
vitamin B1
- Anti-pyridoxine
- Anti-vitamin B12
• Detoxification: heat-labile, readily destroyed by heat
treatment. Some can also be removed by water
extraction.

23. Toxic amino acids
• Disrupt proteins synthesis by competing with protein amino
acids on messenger RNA, but some have additional anti-
nutritional effects.
• a. Mimosine
Source: leaves of ipil-ipil (Leucaena leucacephala)
Effects: inhibit tyrosine decarboxylase, several metal containing enzymes,
reduced growth , feed efficiency, increased mortality.
Detoxification: heat-stable but can be removed by soaking in water for 24-48
hours.
• b. Canavanine
Source: seeds of legume sesbania and jack bean
Effects: food rejection, lethargic behavior , high mortality
Detoxification: soluble in water and can be extracted by overnight soaking
and boiling in excess water followed by decanting .
• c. Dihydroxyphenylalanine
Source: broad/ faba bean and velvet bean
Detoxification: reduction of 80.4% can be achieved by an alkali treatment
(calcium hydroxide) at pH 9

24. Estrogenic factors
• Non steriodal
• Isoflavones: estrogen factors are mostly
isoflavones that occur in form of glycosides in
soybean, genistein most prominent isoflavone.
• Phytoestrogens(sources)
cereals,legumes,oilseeds such as barely, rice,
wheat,corn,soybean,cottonseed.
• Effects: Bind to oestrogen receptors or get
converted into compounds that have estrogenic
effects, phytoestrogen can induce vitellogenesis
• Genistein heat stable, phytoestrogens not serious
threat to fish but should be taken into account
while formulating feed.

25. Thank You