Energy conversions & Feed biochemistry Flashcards
What is energy?
The power driving all functions of an organism
What are some forms of energy?
Heat, Mechanical and Chemical
What can energy not?
Energy cannot be created or destroyed
What are the energy measurements?
Joules and Calories
How many calories in a kcal?
1000
How many calories per gram of carbohydrate?
4
How many calories per gram of fat?
9
How many calories per gram of protein?
4
What does food separate into?
Dry matter and Water
What is Inorganic Dry Matter?
Major and trace minerals
What is Organic Dry Matter
Vitamine, Lipids, Carbs and Proteins
Why should we analyse animal feed?
- Governmental regulations
- Standards
- Labelling
- Food safety
- Authenticity
- Quality control
- Research and development
What are the two classes of minerals?
Macrominerals (Major) and Microminerals (Trace)
What are the Macrominerals?
Calcium, Phosphorus, Sodium, Magnesium and Potassium
What are the Microminerals?
Copper, Iron, Zinc, Iodine, Selenium
What are Macrominerals measured in?
PPH (parts per hundred)
What are Microminerals measured in?
PPM (parts per million)
What do minerals help with?
Skeletal health, protein synthesis, oxygen transport, enzyme reactions
What are the two classes of vitamins?
Water-soluble and Fat-soluble
What are the Water-soluble vitamins?
B group, C
What are the Fat-soluble vitamins?
A, D, E and K
What do the Water-soluble vitamins do?
- Dissolve in water
- Needed for energy release and utilisation
- Excess excreted in urine
What do the Fat-soluble vitamins do?
- Dissolve in fat
- Remain in the body for long periods
- Excess stored in fatty tissue, kidneys and liver
- Lead to toxicity
What are the factors of feed?
- Quality of feed (forage or concentrate)
- Nutrient profile
- Availability of feed
- Palatability
What do all feeds have?
Gross Energy (GE) based on Dry Matter (DM)
What is Gross Energy measured in?
Joules
What affects how much energy an animal gets from a feed?
- Digestibility – some energy lost as waste
- Faeces
- Urine
- Gases (Methane)
- Heat
What are the different types of energy?
Gross energy (GE), Digestible Energy (DE), Metabolisable energy (ME) and Net Energy
What is Digestible energy?
Energy lost via faeces extracted; energy content of digested nutrients
What is Metabolisable energy?
Further loss via metabolism; urinary losses, and methane concern in ruminants
What is Net energy?
Actual energy gained ‘true requirement/value’
What happens when energy isn’t adequate?
- Body condition
- Health depletion
- Production loss
- Animal loss
What is DER?
Animal’s daily requirement
What is BER?
Basal energy rate, the amount of energy required to keep vital organs functioning continuously.
Why is BER difficult to measure?
Requires animal to be completely stress free
What is RER?
Resting energy rate, is the amount of energy an animal needs in a resting state (at least 12 hours after eating).
What is MER?
Maintenance energy rate, resting energy rate plus the energy needed for exercise and digestion
What are the maintenance energy requirements needed for cats and dogs?
Cats = RER x 1.4 | Dog = RER x 2
What type of food do young animals need?
‘energy dense’ food
What is Gross energy?
the total energy content of food, not all is taken by the body
Gross energy - _____ = digestible energy
faecal energy
Digestible - _____ = metabolizable energy
Urinary losses
Metabolizable energy - _______ = net energy
Heat loss
What happens at the end with Net energy?
Net energy is used for maintenance and then production
What are carbohydrates made up of?
Carbon, Hydrogen and Oxygen
What happens to carbohydrates during metabolism?
they are burned to produce energy
What are Carbohydrates present as?
Sugars, Starch (polymers of sugars) and fibre (Non-starch Polysaccharide- NSP)
What does Heparin do?
prevents blood from clotting, contains carb
What does Ribose do?
part of DNA and RNA
Where does no carbohydrate digestion take place?
The stomach
Where does carbohydrate digestion start?
Begins in the mouth by amylase (which is produced by the salivary glands)
Where does the digestion of carbs mainly occur?
Small intestine (through the action of pancreatic and intestinal juices)
What are lipids?
- Lipids consist of a broad group of compounds that are generally soluble in organic solvents but insoluble in water.
- They are major components of adipose tissue, and together with proteins and carbohydrates, they constitute the principal structural components of all living cells.
What can the fatty acids in lipids be grouped into?
Unsaturated fatty acids and Saturated fatty acids
What are the different types of fatty acids?
Short-chan fatty acids, Medium-chain fatty acids, Long-chain fatty acids, Very long chain fatty acids
How many carbon atoms are in short-chain fatty acids?
2 - 6
How are the short-chain fatty acids produced?
mainly produced when dietary fibres are fermented by bacterial hydrolytic enzymes produced by gut microflora
How many carbon atoms are in medium-chain fatty acids?
6 - 12
What can Medium-chain fatty acids form?
Medium-chain triglycerides (MCT)
How many carbon atoms are in long-chain fatty acids?
13 - 21
How many carbon atoms are in very long chain fatty acids?
22 or more carbons
What are fatty acids broke down into?
Triglycerides
Triglycerides are what?
The body’s main source of energy
What can an excess of triglycerides lead to?
High cholesterol
What is excess protein stored as?
Fat
What are some roles of protein?
- Growth and repair
- Production of DNA, hormones and antibodies
- Source of essential amino acids
What are amino acids?
The building blocks of proteins are amino acids, which are small organic molecules that consist of an alpha (central) carbon atom linked to an amino group, a carboxyl group, a hydrogen atom, and a variable component called a side chain
What are the essential amino acids?
Arginine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine + Taurine in cats
