Feeding animals and energy Flashcards
Why do animals need food?
- for building and maintaining cellular and metabolic machinery
- growth, reproduction and lactation
- energy
What is a nutrient?
Any chemical element or compound in the diet that supports normal reproduction, growth, lactation or the maintenance of life processes
What are the 6 classes of nutrient?
- Water
- Protein
- Carbohydrate
- Lipids
- Vitamins
- Inorganic elements
For feeds, vets need to be able to give advice on…?
- cost
- choice
- interaction, observation
- storage
- vet prescription diets
How is a carnivore adapted for its diet?
- Grasping canines, cutting carnassial and powerful bite
- monogastric digestive system
- stomach conducts physical and chemical digestion
What is the feeding pattern of ruminants?
1/3 of grazing, ruminating and resting
What do herbivores need to be adapted to digesting a lot of?
Fibre - B-linked polysaccharide
What is fermentation?
Breakdown of material by microbes
What are the 3 biggest products from the rumen bacteria?
Volatile fatty acids, methane and CO2
What is the result of rapidly fermentable feeds?
Excess VFA synthesis
Describe the process of chewing the cud
- regurgitate bolus to mouth
- fluid component re-swallowed
- fibrous component masticated 40-70 times
- mechanical breakdown, increase SA, increase saliva
Which 3 components make up the hind gut?
Caecum, large intestine and colon
What are the advantages to rumen fermentation?
- better fibre digestion
- better absorption of VFA’s
- Utilise microbial protein
What is the main advantage of a hind gut fermenter?
- Enables animals to utilise otherwise non-accessible nutrients from forage feeds after absorption
How can you evaluate digestion (absorption) of a food stuff?
Compare the quantity of nutrients ingested with the quantity of those same nutrients excreted in faeces
What is the problem with evaluating digestion?
Faeces also contain gut cells, bacteria, enzymes, this causes an underestimation of actual food nutrient absorption
What factors affect digestibility?
- Animal factors - species, plane of nutrition/gut transit time
- Food factors - fibre content
- Feed preparation factors - heat treatments, cold treatments, chemical treatments
What is fresh weight and dry matter?
Fresh weight = mass given to animal
Dry matter = mass with all water molecules removed
Compare anabolic and catabolic reactions
Anabolic = require energy, end products are complex Catabolic = produce and generate energy, larger molecules are broken down
When is an animal said to be in a total energy balance?
When total energy provision = total energy needs
If energy provision > energy needs what happens?
Positive energy balance - stores energy
What is a calorie?
The heat required to raise the temp of 1g of water by 1 degree
What is metabolizable energy? and what is it affected by?
The energy assimilated by the animal and available to fuel metabolism
- animal factors
- factors that affect digestibility
- methane losses
- protein intake
- nitrogen balance
- feeding levels
- food preparation
What is meant by the heat increment of feeding? give examples
Digesting food takes energy - the specific dynamic action of feeding
- prehension and mastication
- increased gut contraction
- increased production and release of digestive enzymes
- catabolism of nutrients
- absorption across the gut wall
What is net energy and how is it calculated?
- The energy available to the animal when the costs of digestion, metabolism, and wastage have been accounted for
- thermic energy must be subtracted from ME
When measuring basal metabolic rate how must an animal be? What is used to measure it?
- not moving
- not stressed
- within the thermal neutral zone
- post absorptive state
- a direct or indirect calorimeter
