ANIMAL NUTRITION

Animal Nutrition

Nutrients & Diet Digestive System

Lesson 1Learning Objective1.List the chemical elements which make up carbohydrates, fats and

proteins.2.List the principle sources of, and dietary importance of carbohydrates,

fats, proteins, vitamins (C and D), mineral salts (calcium and iron), fibre (roughage) and water.

Outline Need for food Carbohydrates Fats Proteins

Need for Food

•To provide energy for vital activities of body•To replace energy lost•To make new cells and tissues•To repair tissues•To maintain healthy body•To prevent deficiency diseases

7 Classes of Food

•Carbohydrates•Fats•Proteins•Vitamins•Dietary fibre•Mineral Salts•Water

Carbohydrate

Sources:

Carbohydrate

Uses of carbohydrates:• Source of energy (17 kJ/g)• Formation of nucleic acids (DNA)• To be converted to other organic

compounds, e.g. amino acids and fats• Formation of supporting structures, e.g.

cellulose cell wall.

Carbohydrate

Chemical elements:• Carbon (C)• Hydrogen (H)• Oxygen (O)

Carbohydrate

Carbohydrate

Monosaccharide PolysaccharideDisaccharide

E.g. glucose, fructose, galactose

E.g. starch,glycogen,cellulose

E.g. maltose, lactose, sucrose

Monosaccharide

Disaccharide

Polysaccharide

Stored food• In animals, glucose is stored in the form of glycogen.• In plants, glucose is stored in the form of starch.

Why are glycogen and starch suitable as storage materials?

– Easily hydrolysed to glucose when needed– Large molecules and insoluble in water hence they do not

change the osmotic pressure in cells– Structures are compact so they occupy less space

Fats

Sources:

Fats

Uses of fats:• Source of energy (37 kJ/g)• Insulating material to prevent

excessive heat loss• Prevent water loss from skin's

surface, by producing oily secretions over the surface.

• A solvent for fat-soluble vitamins and hormones

Fats

Chemical elements:• Carbon (C)• Hydrogen (H)• Oxygen (O)

Fats

Fats

Chemical elements:• Carbon (C)• Hydrogen (H)• Oxygen (O)

Fats

Fats

Saturated Unsaturated

Fats that contain fatty acid chains

with only single bonds

Fats that contain fatty acid chains

with doublesingle bonds

Saturated Fats

• Sources: Meats, dairy products, chips.• Not heart-healthy• Can raise LDL cholesterol (“bad”

cholesterol)

Unsaturated Fats

• Sources: Nuts, avocadoes, olives• Heart-healthy• Can lower LDL cholesterol (“bad”

cholesterol) and raise HDL cholesterol (“good” cholesterol)

Proteins

Sources:

Proteins

Uses of proteins:• Source of energy (17 kJ/g)• Synthesis of new protoplasm• Synthesis of enzyme and hormone• Synthesis of antibodies to combat

diseases

Proteins

Chemical elements:• Carbon (C)• Hydrogen (H)• Oxygen (O)• Nitrogen (N)• Sulphur (S)• Phosphorus (P)

ProteinsProteins are comprised of amino

acids linked together.

There are 20 different amino acids used to make proteins.

Amino acids can be broken into 2 types:• Essential amino acids (8)– Amino acids that cannot be synthesised by human body.

• Non-essential amino acids (12)– Amino acids that can be synthesised by human body.

ProteinsDeficiency:Kwashiorkor

Signs and symptoms:• Swollen abdomen• Enlarged liver• Changes in pigmentation of skin and hair• General drowsiness• Cracked and scaly skin

Learning Objective

1.List the chemical elements which make up carbohydrates, fats and proteins.

2.List the principle sources of, and dietary importance of carbohydrates, fats, proteins, vitamins (C and D), mineral salts (calcium and iron), fibre (roughage) and water.