AN OVERVIEW OF
NUTRIENTS
Nutrients
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

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Carbohydrates
Proteins
Lipids
minerals
vitamins
water
Dry Matter
1. Organic compounds:






Carbohydrates
Lipids
Proteins
Nucleic acids
Vitamins
Organic acids
2. Inorganic Compounds:

- Minerals
Proximate Analysis
Moisture
 Ash
 Crude Protein
 Ether Extract
 Crude Fiber

Nitrogen Free Extract (NFE): Calculated
Proximate Analysis
Dried Sample
Kjeldahl (CP)
Ether Extraction (EE)
Fat Free Residue
Boil in acid
Ash
Crude
Fiber
Boil in alkali
Crude Fiber + Ash
Crude Fiber
Mono-gastric Animals ……
 Ruminant Animals …..?

Detergents
• NDF (cell wall contents): gut fill
• ADF (NDF minus H-cellulose): digestibility
• ADL ???
Carbohydrates





Primary component of livestock feed
Renewable resource as they are converted to CO2
and H2O.
Primary carbohydrate in plants is glucose
Comprise 70% of forage dry matter and 80% of
concentrates
Carbohydrates are a source of energy but there is
no specific requirement for them
Carbohydrates



Carbon, hydrogen, oxygen
Monosaccharide five pentose or six carbons hexose.
Disaccharides, polysaccharides
Starch
Carbohydrates
1.
Sugars:
Mono (# C) : C3, C4, C5, C6, C7
Pentoses: Ribose; Hexoses: Glu, Gal, Man, and Fru
Disaccharides: Sucrose, Lactose, Maltose
Tri: Raffinose, Kestose
Tetra: Stachyose
Carbohydrates
Polysaccharides
NonSugars
Homoglycans
Pectic Substances
Heteroglycans
Arabinans
Xylans
Glucans
Hemicellulose
Complex
Carbohydrates
Gums
Starch, Dextrin,
Chondroitin
Glycogen,
Glycolipids
Glycoproteins
Cellulose
Lipids

General
 Soluble
in ether
 Contain Carbon, Hydrogen and Oxygen C, H, O
 High proportion of carbon and hydrogen
 ~2.25 times the energy of carbohydrate per gram
Lipids

Classification
 Simple
 True
fat - esters of glycerol
 Waxes - esters of other alcohols

Classification
 Compound
- groups other than alcohol and FA's
 Phospholipids
- phosphoric acid and nitrogen
 Glyco-lipids - Carbohydrates and nitrogen
 Lipoproteins- proteins and lipids
Lipids
Glycerol-based
Complex
Simple
Non Glycerol-based
Phosphoglycerids
Fat/ Oil
Waxes
Glycolipids
Steroids
Lecithin
Cephalin
Galactolipids
Glucolipids
Terpens
Sphingomyelin
Prostaglandins
Lipids

Classification
 Derived
lipids
 Fatty
acids
 Sterols

Fats and Oils
 Fat
vs Oil - Melting point only difference
 Fat = glycerol + 3 fatty acids
Lipids
Lipids

Characteristics of fat due to type and proportion of
different fatty acids
 Chain
length
 Longer



chains result in higher melting points.
Butyric C4H8O2
Palmitic C16H32O2
Stearic C18H36O2
Examples: Fatty acids

Oleic
C18:1
 CH3-(CH2)7-CH=CH-(CH2)7-COOH

Linoleic
C18:2
 CH3-(CH2)4-(CH=CH-CH2)2(CH2)6-COOH

Linolenic C18:3
 CH3-CH2-(CH=CH-CH2)3(CH2)6-COOH

Arachidonic
C20:4
 CH3(CH2)4(CH=CHCH2)4(CH2)2COOH
Lipids



Iodine number- A measure of un-saturation.
Saponification number- A measure of chain length.
The amount of alkali required to saponify 100
grams of fat.
Other lipids: Sterols
 Cholesterol.
Mainly in animal tissues.
 Hormones. Very little quantitatively.
 Ergosterol. A sterol in plants which can form vitamin D
through the action of ultra violet light
Other lipids

Carotenes.
 Yellow
colored substances common in plants that can be
converted by animals to vitamin A.

Phospholipids.
 Most
abundant in blood, brain, liver and egg yolk.
Can be utilized.
β-carotene
Phospholipids
Other lipids

Chlorophyll
 Green
colored substance in plants - No feed value for
animals.

Waxes
 Surface

of leaves and fruits.
Essential oils.
 Give
plants their odors and tastes.
Proteins
 Long
chains of Amino Acids.
 Contain Nitrogen, carbon, hydrogen, oxygen, and
sometimes sulphur.
 Lose tertiary structure when heated.
Proteins



Globular
Fibrous
Conjugated
 Structural
Transporter
Catalytic
Amino acids
Traditionally
 Indispensable
 Dispensable
Totally
Indispensable
C-skeleton
Conditional
Immaturity
Newer Definition
Human Nutrition
Acquired
dispensable
Disorders
AA intake
Other N compounds

Non protein Nitrogen (NPN)

Urea
 Nucleic acids
 DNA
 RNA
Additives
Not as nutrients
Some examples
 Antibiotics: growth stimulator/ disease control
 Anti-parasitic drugs
 Synthetic Antioxidants
 Antifungal agents
 Enzymes: improved digestion

Digestion
Primary Enzymes for Carbohydrates
Food Source
Enzyme
Origin
Product
Starch, glycogen,
dextrin
Amylase
Saliva &
pancreas
Maltose &
Glucose
Maltose
Lactose
Sucrose
Maltase
Lactase
Sucrase
• Ruminants do not secrete much sucrase
• Inducible enzymes
• Lactose intolerance
SI
SI
SI
Glucose
Glucose &
galactose
Glucose &
fructose
Primary Enzymes for Proteins
Food
Source
Enzyme
Origin
Product
Milk protein
Rennin
Gastric mucosa
Curd
Proteins
Pepsin
Gastric mucosa
Polypeptide
Trypsin
Chymotrypsin
Pancreas
Pancreas
Peptides
Peptides
Carboxypeptidase
Aminopeptidase
Pancreas
Small intestine
Peptides &
amino acids
Polypeptides
Peptides
Primary Enzymes for Lipids
Food
Source
Lipids
Enzyme
Origin
Product
Lipase & colipase
Pancreas
Monoglycerides
& free fatty acids
Nutrient Digestion - Lipids
Large Lipid Droplet
Action of bile salts
Lipid emulsion
Small
Bile salts & pancreatic lipase
and colipase
Water soluble micelles
Digestion of Lipid


Bile salts emulsify lipids
Pancreatic lipase acts on triglycerides


Triglycerides
acids
sn-2 Monoglyceride + 2 fatty
Pancreatic colipase
Activated by trypsin
 Interacts with triglyceride and pancreatic lipase



Displaces bile
Improves activity of pancreatic lipase
Importance of Pancreas for Digestion

Produces enzymes responsible for
 50%
of carbohydrate digestion
 50% of protein digestion
 90% of lipid digestion

Produces bicarbonate for neutralization of chyme in
duodenum
Digestive enzymes; summary