Nutrition I: Overview and Feed Types

Question 1

6 nutrient essential:

Answer 1

Water
	Energy		
	Protein (Amino Acids)
	Minerals
	Vitamins
	Essential Fatty Acids

Question 2

Chemical composition of the organic component of feed

Answer 2

Carbohydrates

Lipids

Proteins

Nucleic Acids

Organic Acids

Vitamins

Question 3

Feed is made up

Answer 3

of dry matter and water

Question 4

Function of water

Answer 4

Cell turgor (structure)
Transport of nutrients
Chemical reactions
Temperature regulation
Milk Production

Question 5

Water allowance for farm animals increases with

Answer 5

Temperature

Question 6

Water is provided by

Answer 6

Water in food
Metabolic water
Drinking water

Question 7

Protein

Answer 7

Proteins are polymers of amino acids

20 different amino acids required to produce most proteins

Diet must supply essential amino acids

Proteins are extremely diverse on terms of function (eg structural or enzymes)

Requirement is continual due to protein turnover

For a 40 kg lambs growing 250g/day:
- 18 kg is muscle tissue in which there is 3.6 kg protein

Dairy Cow producing 50kg milk/day
- Milk is 3.3% protein, therefore she is producing 1.65 kg protein / day

Question 8

Function of minerals

Answer 8

Three main functions:

Structural activity
Catalytic activity (prosthetic groups & co-enzymes)
Electrolytes and buffering

23 ‘essential’ minerals elements

Classified as either major (g/kg DM) or minor (mg/kg DM) elements

Question 9

Criteria for Essentiality

Answer 9

Present in healthy tissue of living matter
Constant concentration in tissue and fluids between animals
Withdrawal produces similar physiological and structural abnormalities regardless of species
Abnormalities are accompanies by specific biochemical changes
Addition of physiological amounts of the mineral will prevent or reverse the abnormalities associated with its withdrawal

Question 10

Major Minerals in Animal Nutrition

Answer 10

Calcium
	Phosphorus
	Magnesium
	Sodium
	Chlorine
	Potassium
	Sulphur
	(g/kg DM diet)

Question 11

Na+ and Cl- exists mostly in

Answer 11

Extra cellular fluid

Question 12

K+ and Po4 2- exists mostly in

Answer 12

Intracellular. Fluid

Question 13

Trace Elements in Animal Nutrition

Answer 13

Cobalt
	Copper
	Iodine
	Iron
	Manganese
	Selenium
	Zinc
	(mg/kg DM diet)

Question 14

Additional Trace Elements in Animal Nutrition

Answer 14

Requirements of these trace elements is extremely small and there is no documented deficiency

Chromium
	Molybdenum
	Aluminum
	Arsenic
	Boron
	Fluorine
	Nickel
	Tin
	Vanadium

Question 15

Fat soluble vitamins

Answer 15

Vitamin A
Vitamin D
Vitamin E
Vitamin K

Question 16

Water soluble vitamins

Answer 16

Thiamin
	Riboflavin
	Niacin
	Vitamin B6
	Pantothenic acid
	Biotin
	Folicin
	Vitamin B12  
	Choline
	Vitamin C

Question 17

Most vitamins are unstable and therefore…

Answer 17

Destroyed by exposure to heat and light.
Storage and processing
important

Question 18

Vitamin E in the membrane

Answer 18

Vitamin E partitions into lipoproteins and cell mem- branes, where it represents a minor constituent of most membranes. It has a major function in its action as a lipid antioxidant to protect the polyunsaturated membrane lipids against free radical attack. Other functions are believed to be to act as membrane stabilizers by forming complexes with the products of membrane lipid hydrolysis, such as lysophospho- lipids and free fatty acids.

Question 19

Deficiency of Thiamin

Answer 19

Signs include anorexia, neurological disorders (Cerebrocortical necrosis – CCN) which is a postural problem
Common in newly weaned ruminants due to thiaminase enzyme produced in the rumen

Thiaminase also found in some plants such as bracken or horsetail which can induce deficiencies

Question 20

Essential fatty acids

Answer 20

There are 2 essential fatty acid groups: n-6 and n-3 that must be supplied in the diet

n-6 starts with linoleic acid (C18:2)
n-3 starts with α-linolenic acid (C18:3)

These fatty acids are a precursor for a series of hormone such as prostaglandins and thromboxane

Question 21

Energy is required for

Answer 21

Formation of:-
		Proteins (peptide bond formation)
		Triglyceride
		Glycogen
	Muscle contraction 
	Transmission of nerve impulse, absorption of 			nutrients, sight etc

Question 22

Sources of energy

Answer 22

Sugars (monosaccharides)
Fats (triglycerides)
Proteins / amino acids
Volatile fatty acids

Question 23

Feed. Can. Be made up of

Answer 23

Forages
Straights
By-products
Compound feeds (complete or complementary)

Question 24

Carbohydrates are most abundant in…

Answer 24

Sugar beet 853 g/kg
Barley 849 g/kg
Grass 684-760 g/kg

Question 25

Sources of carbohydrates

Answer 25

Sources of Carbohydrate
Animal products
minor component of meat but present in milk (lactose)
Plants – Two main classes
Storage of energy - starch and sugars
Structural – Cellulose and hemicellulose