This document discusses various antinutritional factors found in feed ingredients that can interfere with animal nutrition. It defines antinutritional factors and classifies them based on their chemical properties and effects. The main groups discussed are proteins like protease inhibitors and lectins, glycosides like saponins and cyanogens, phenols like gossypol and tannins, and other factors like phytates, oxalates, amylase inhibitors, and antivitamins. Specific antinutritional factors are explained in more detail, including their chemical structure, sources, and impacts on digestion and health. Methods to reduce their effects like heating, soaking and addition of other compounds are also summarized.

1. ANTINUTRITIONAL
FACTORS
Biochemistry & Metabolism

2. Defination
Anti nutritional factors (ANFs) may be
defined as those substances present in
the feed which by themselves or their
metabolic products interfere with the
feed utilisation, reduce production or
affects the health of animal

3. Classification
Classification based on their chemical properties
Group I - Proteins
1. Protease inhibitor
2. Lectins (Heamagglutinins)
Group II – Glycosides: compounds in which sugar bonded
to another non sugar (Aglycon) through glycosidic bond
1. Saponin
2.Cynogens
3.Glucosinolates

4. Group III - Phenols
1. Gossypol
2. Tannins
Group IV - Miscellaneous
1. Antimetals
2.Antivitamins

5. Classification based on their effect on nutrient
utilisation
Substances depressing digestion & utilisation of
proteins
a. Protease inhibitors
b. Heamagglutinins
c. Saponin
d. Polyphenolic components

6. Substances depressing digestion & utilisation of
Carbohydrates
1. Amylase inhibitors
2. Phenolic compounds
3. Flatulence factor

7. Substances depressing digestion & utilisation
of Minerals
1. Phytic acids
2. Oxalic acid
3. Glucosinolates
4. Gossypol

8. Substances depressing digestion & utilisation
of Vitamins
1. Ant vitamin A,D,E,K
2. Ant vitamin B1,B6, B12 and Niacin
Substances that stimulate immune system
Antigenic factors

9. Substances inhibiting the digestion and Utilisation of
Protein
Protease Inhibitors
 Found in legumes such as soybean, mungbean and peas,
but also in cereals, potatoes, and other products

10.  Types of protease inhibitors
1. Bowman‐Birk inhibitor
2. Kunitz inhibitor
Bowman‐Birk inhibitor
 71 amino acids and seven disulfide bonds
 Molecular weight - 6,000 -10,000
 Two active sites, one specific for trypsin and the other for
chymotrypsin
 Inhibition is non-competitive

11. Kunitz inhibitor
 181 amino acids and two disulfide bonds
 Molecular weight - 20,000 - 25,000
 Inhibit trypsin, lesser extent chymotrypsin and inactive
against other endopeptidases
 Inhibition is both reversible and pH dependent
 Optimal pH for trypsin binding - 8.0

12. Method of Detoxification
Heating, Auto calving,
Steam boiling for 60min
Auto calving at:
5psi for 45 min,
10 psi for 30 min,
15 psi for 20 min

13. Lectin/ Heamagglutinins
 A lectin is a sugar binding protein of non immune origin
that agglutinates cells or precipitates Glycoproteins
 Found in legumes - beans, peas, lentils
 Grains - wheat, rice, oats, rye, millet, corn
 Able to combine with glycoprotein components of red
blood cells (RBC) causing agglutination of cells

14. Soybean agglutinin (SBA)
Bind with brush border surfaces
( In the distal part of small intestine)
↓
Damage small intestinal villi
↓
Irritation and over-secretion of mucus
in the intestines
↓
Impaired absorptive capacity
of the intestinal wall

15. Ricin
 Found in caster bean (Ricinus communis)
 Consist of two polypeptide chains
 A-chain (RTA) - 267 amino acid
 B-chain (RTB) - 262 amino acid
 Both chains are connected by a disulphide bond

16. Chain B
( Galactose binding subunit )
↓
Bind to cell membrane of target cell
(cell surface receptors containing terminal galactose )
↓
Transport of toxin-receptor complex
into the cytoplasm

17. Chain A
(Enzyme ,adenosine-N-glycosidase )
↓
Depurination of r RNA
(loss of adenine from rRNA)
↓
Stop protein synthesis
↓
Cell death
Detoxification: Steam Treatment for 60 min

19. Saponins
 Consist of a polycyclic aglycones attached to one or
more sugar side chains
 The aglycone part, is either steroid (C27) or a triterpene
(C30)

20.  Found in Lucerne, soybeans, peanuts, sugar beets
 Bitter taste, foaming in aq. solution, haemolyse R.B.C.
 Foaming ability is due to combination of a hydrophobic
(fat-soluble) aglycone part and a hydrophilic (water-
soluble) sugar part

21. Saponin
(in high amount)
↓
Lowering the surface tension
of ruminal contents
↓
Accumulation of gas in rumen
↓
Bloat / Tympany
Prevention: 1. Low level of feeding
2. Avoid feeding young plant or wilted plants
can be fed
3. 1-2 kg dry fodder should be fed before feeding
Lucerne

22. Tannins
 Polyphenolic substance with high molecular weight
term was coined by Seguin 1796
 It forms stable complex with proteins, Cellulose,
Hemicellulose and pectin
 Binds with enzymes involved in protein digestion
 Binds with salivary enzymes causes astringency
 Tannins are of two types
 1. Hydrolysable tannins
 2. Condensed tannins

23. Hydrolysable tannins
Contain carbohydrate moiety in which OH group is
esterified to gallic acid, digallic acid
 Hydrolysed by water, acids, bases, and enzymes
Basic unit – Gallic acid
 At the center of a hydrolyzable tannin molecule, there is
a carbohydrate
 Eg. Tannin in oak Gallotannins, Ellagitannins

24. Condensed tannin
 Polymers of flavans and never contain sugar
residues[
 Non-hydrolyzable
 Eg. Tannin in sorghum flavo beans salseed babul
seed mango kernals contains Epicatechin and
catechin

25.  Tannins are found in sorghum, salseed meal, mustard
oil cake, lucerne meal in high amount (may be 2% to 10
%)
 Tannins are astringent in nature so they cause a dry
sensation in mouth by reducing the lubricant action of
saliva.
 They binds the protien thus inhibitors of proteolytic
enzyme.
 It depress cellulase activity thus affect digetion of crude
fiber.

26. • Signs of Tannin poisoning
• Anorexia, clear watery discharge from nasal
cavity, rumen stasis, frequent urination, initial
constipation followed by excretion of dark
mucoid bloody feces

27. Detannification
Usually tannin present in outer layer of seed
Physical treatment- Soaking and Cooking
– Anerobic Storage of sorghum grains for 2-9 days
Chemical Treatment- Addition of complexing agents
Poly ehylene glycol
Poly vinyl pyroldane
Alkali, Formaldehyde Acetone H2O2 reduces Tannin

28. Cyanogens
Usually plant contain trace amount of cyanide as cyanogenic
glycoside which usually non toxic but when it is hydrolysed
to prussic acid or HCN by enzyme usually present in the
same plant or by rumen microbes
Lower amount of HCN is rapidly absorbed and eliminated
through lung but greater part detoxified in liver by
conversion to thiocyanate
Toxic principle: Cyanogenic glycosides (amygdalin, prunasin,
dhurrin, linamarin)
 Found in sorghum, velvet grass, lima bean, white clover,
arrow grass, maize
 HCN is formed when the glycosides are hydrolyzed by
enzymes (β – glucosidase) in plants or by rumen
microorganisms

29. β - glucosidase
 Cyanogenic glycosides → sugar + aglycone
Hydroxynitrile lyase
 Aglycone → HCN + aldehyde or ketone
 CN¯ + Fe (+3) of cytochrome oxidase
↓
prevents transport of electrons
from cytochrome C oxidase to oxygen
↓
stop cellular respiration & cell death

30. Ruminants are more susceptible to HCN in non
ruminants HCL destroy the enzyme required
Symptom: Generalized muscle paresis
Abdominal pain, Vomiting
Respiratory Distress and death
Prevention: Avoid feeding immature grasses of
Jowar, Sudan
Rx: 3g NaNo3 & 15g Sodium thiosulphate in 200ml of
H2O to cattle as IV –Cattle
1g NaNo3 & 2.5g Sodium thiosulphate in 200ml of
H2O to cattle as IV –Sheep

31. Anti metals

32. Glucosinolates
The Glucosinolates are a class of organic
compounds that contain sulfur and nitrogen and
are derived from glucose and an amino acid

33.  Secondary metabolites of almost all plants of
the family Brassicaceae, Capparidaceae, Caricaceae and
Euphorbiaceae as natural pesticide on defence against
herbivores
 There are 120 different Glucosinolates which are Synthesized
from certain amino acids, mainly methionine, but
also Alanine, Leucine, or Valine.
 Plant contain myrosinase which in presence of water cleve
glucose of glucosinolates reaming molecules convert
thiocyanates to iso thiocyanates or nitrile which are active
substance for defence to prevent damage to plant itself it is in
separate compartment only under stress it is released.
 This in fact is used as natural pesticide and also for prevention
of cancer which is under investigation.

34. Thiocyanate ions
↓
Decrease iodide uptake
by competitive inhibition
↓
Reduced secretion of
thyroxine and triiodothyronine
↓
Increased release of thyrotropin
(by negative feedback)
↓
Stimulation of thyroid gland
↓
Goitre

35. Gossypol (C30H30O8) is a polyphenolic aldehyde
 Found in pigment gland cotton plant.
 There are 15 other closely related compound among them
gossypol is abundant
 Cellwall of pigment gland made up of cellulose, pectin and
hemicellulose and uronic acid which is resistant to rupture
so it goes with meal upon heating it binds with lysine
 Free gossypol is important as bound gossypol is inactive
but it lower the BV of protein

36.  Gossypol make complex with metal ions like
iron
↓
Reduced Hb content & so reduced O2 carrying capacity
of blood
↓
Reduced growth rate
 Gossypol is inhibitor for several dehydrogenase
enzymes

37. It is highly toxic to monogastircs like pig and
rabbits are more sensitive horse and ruminants
are resistant due to formation of stable
complex with soluble protein
In Poultry – Olive green yolk reaction b/w
gossypol & yolk iron
Cyclopropenoid FA of CSM causes pink
albumin

38. Effect in non Ruminants:
– Depressed appetite
– Loss of weight
– Liver and lung lesions- congestion and hemorrhages
– Cardiac irregularities
– Anemia
Whole CSM contain 1.09-1.53% gossypol of which
0.19% is free
In Poultry 0.06% causes depressed growth
0.1% severe effect
0.15% reduces egg production
In Pigs 0.01% reduced growth
0.015% toxic symptoms

39. Prevention:
Addition of FeSO4 1:1
Heat treatment decreases content but
availability of lysine reduced because of
reaction b/w Aldehyde grp of gossypol with
lysine

40. Phytic acid
 Phytic acid (known as Inositol Hexaphosphate (IP6),
 Principal storage form of phosphorus in
many plant tissues especially bran and seeds
MW: 660.03
Formula: C6H18O24P6

41.  Phosphorus in phytate form is not bioavailable to non
ruminant animals because they lack the
digestive enzyme phytase
 It has a strong binding affinity to minerals such
as calcium, magnesium, iron, and zinc
 When a mineral binds to phytic acid, it becomes
insoluble, precipitates and will be non-absorbable in the
intestines
 This process can therefore contribute to mineral
deficiencies

42. Oxalic acid
 Molecular formula - C2H2O4
 Found in Paddy straw, bajra, Napier grass etc.
 In G.I.T.
oxalic acid + calcium (present in feed) →
calcium oxalate (insoluble)
So calcium unavailable to absorption

43.  In blood
 oxalic acid + calcium (present in blood) →
 calcium oxalate (insoluble)
 Insoluble calcium oxalate may crystallize in tissues,
mainly kidneys
 Also produce condition hypocalcaemia

44. Substances depressing digestion & utilisation
of Carbohydrates
1. Amylase inhibitors
About 800 plant species have been reported to
possess amylase inhibitor properties.
A wide range of plant-derived principles
belonging to compounds, mainly alkaloids,
glycosides, galactomannan gum,
polysaccharides, hypoglycans, peptidoglycans,
glycopeptides and terpenoids.
Tamarindus indica Azadirachta indica

45. Showed that the potency of inhibition is
correlated with the number of OH groups on
the B ring of the flavonoid skeleton.
The interaction occurs with the formation of
hydrogen bonds between the hydroxyl groups
in position R6 or R7 of the ring A and position
R4’ or R5’ of the ring B of the polyphenol
ligands and the catalytic residues of the
binding site and formation of a conjugated -
system that stabilizes the interaction with the
active site.

46. Tannins are another heterogenous polyphenol
group widely distributed in the plant kingdom
that are often present in unripe fruits, but can
disappear during ripening.

47. 2. Flatulence factor
Plants like Raddish, Cabbage, Immature
Chillies, Alpha Alpha, Rape seed wheat and
many beans
Contains non starch polysacchrides like
arabinoxylans, Raffinose, beta-glucans,
cellulose, chitins, guar inulin.
Responsible for flatulence

48. Antivitamins
Antivitamin A
 Enzyme – Soybean lipoxygenase
 Found in soybean
 It catalyse oxidation of carotene ( precure of vit. A)
Anti vitamin E
Kidney bean;- lead to muscular destrophy in chicks and
lambs
Autoclaving removes

49. Antiniacin
 Known as Niacytin
 Found in cereals
 It is bound forms of the vitamin niacin
 Complexes of niacin with polysaccharides and
peptides or glycopeptides
 Not hydrolysed by intestinal enzymes, so
biologically unavailable

50. Antivitamin K
 Dicoumarol is an anticoagulant that functions as
a Vitamin K antagonist
 Found in spoiled sweet clover hay

51.  Coumarin (found in sweet clover) is converted in to
dicoumarol by fungi
 Dicoumarol reduses the prothombin level in blood and
affects blood cloting

52. Anti pyridoxine
 1 – amino D – proline
 Found in linseed
 Occurs naturally in combination with glutamic acid
 Complex is called linatine
 Molecular weight: 259
 Molecular formula: C10H17N3O5

53. Nitrate poisoning:- oat hay poisoning
Nitrate –Rumen Bacteria----------- Nitrite
Hb ---- meth Hb
Affects O2 transport
Blood becomes chacolate brown and brownish
discoloration of Non pigmented areas of skin
Death may be due to anoxia
Source: Water contaminated with industrial
waste, corn stalk Oat hay
Rx: I/v methylene blue which converts back
Meth Hb to Hb

54. Mimosin toxicity:
Source: Subabul contain toxic amino acid @ 2-
5% in leaves
On mastication and rumen degradation by
microbes a goitrogen 3 OH 4 Pyridine (3,4
DHP) is formed
Toxicity Symptoms: Alopecia, increased
salivation enlarged thyroid abortion cataract
Rx: Drying at high temp
Ensiling; Addition of FeSO4
Ruminants in Indonesia & Hawaii poses microbes in
rumen which can rapidly degrade DHP

55. Antigenic Proteins:
Certain plants contain proteins capable of
crossing the intestinal barrier and elicit
antigenic activity in case of soybean antigenic
protein glycin and conglycine they are resistant
to thermal treatment and enzymatic action on
absorption lead to hypersensitivity reaction
Condition seen in piglets and calves after
feeding heated soybean further lead to
digestive disturbance

56. Seleno amino acids:
Found in Se toxicity areas of Haryana, Punjab,
UP particularly in Buffaloes during lean season
due to feeding of paddy straw grown in Se rich
soil.
It is called as Degnala Disease charecterised
by necrosis of body extrimities such as mouth
ear tips tail ends and hooves
In the rumen instead of cystein and methionine
seleno cystein seleno methionine is formed
Lead to AA imbalance

57. Lathyrogens
Found in chik pea and Vitch
Effects are it is derivative of AA acts as
antogonist to glutamic acid a neurotransmitter
in brain
Leads to crippling paralysis also called as
crippling disease called Neuro lathyrism
Lathyrogens also decreases collagen and
elastin cross linkage by inhibinting lysyl
oxidases lead to thin bone called
Osteolathyrism