Lecture 3+4 Flashcards
When we are talking about forages who are we talking about?
Herbivores, omnivores
What expenses of food are on a farm? What %?
75%
When assessing feed quality, what do we look at?
-Crude protein (typically the most expensive in the diet)
-Fibre
-Some assessment of digestibility
Why do we have an interest in feed composition ?
To allow comparison of feeds on a specific basis
List animal requirements:
-maintenance
-growth
-pregnancy and reproduction
-production
List the 2 main approaches in assessing the value of feedstuff:
1-Labratory assessment
2- Animal assessment
List the two laboratory assessments for assessing the feedstuff:
1- Chemical evaluation
2- In vitro digestion
Who created the chemical evaluation of feedstuff?
-Detergent
(Van Soest) system
Dr. Peter Van Soest
What is ash?
Minerals
NDS - what does it stand for?
Neutral detergent soluble ,
pH- 7
NDF- definition
Neutral Detergent Fibre
What solubilised in the NDS?
-Sugar
-Starches
-Organic acids
What didn’t solubilise in the NDF?
-NDSF
-Fructans
-Glucans
-Pectic substances
If a plant have more NDS, what does that make the plant?
More digestible
What do you put into the NDF to break it down?
Acid detergent extraction
When you put acid detergent extraction into NDF what comes out ?
Soluble things come out as - Hemicellulose
Insoluble things that come out - Acid detergent fibre (ADF)
-Cellulose
-lignin
-Fibre - bound N
-Heat - Damages N
Where are all the soluble nutrients of a cell?
All soluble nutrients are inside the cell
Why are we so interested in NDF?
It is an estimate of the digestibility of a plant
Why do plants produce NDF?
-Protection
-Structure
-Metabolic function
Once the barrier of the plants NDF breaks what happens? And what problems can arise ?
Bacteria, fungi infiltrate and
-produce mycotoxins
Why is mycotoxins bad?
Bad for the animals that eat it
Why is seaweed so good?
Doesn’t have much structural carbohydrate, highly digestible
How does a plant protect itself from dehydrating?
Creates more NDF
-Lignin reduces the loss of water
What stimulated lignin production?
Drought
What does lignin provide?
“Hydrophobic Surface”
It allows plants to transport water against gravity to heights greater than 100m
If it goes into neutral solution what can we nearly guarantee about the nutrients?
There highly soluble
In the Detergent (Van Soest) system whats the neutral detergent ?
Recovers major plant cell wall components
Recovers all other organic constituents
In the Detergent (Van Soest) system whats the acid detergent ?
Recovers cellulose , lignin, and lignin-N complexes
Removes hemicellulose and fibre-bound protein
Whats the cell contents of the Van Soest System soluble in?
Soluble in neutral detergent
What is there a close relationship between?
Solubility and digestibility
In the Van Soest System , what is the cell wall constituents insoluble in?
Insoluble in Neutral Detergent eg:
1- Soluble in acid detergent
2- Acid- detergent fibre (ADF)
Whats majority of the faeces ??
Water
What is also in faeces?
Micro organisms and then some proteins
What is the components of ADF?
-Cellulose
-Lignin
What does ADF never include?
Hemicellulose
Whats the fibrous component of ADF?
-Least digestible fibre portion of forage
Feeds with higher ADF are…
Lower in digestibility
ADF is often used to calculate what?
The content of feed because energy content of feed is related to its digestibility
In VIVO def
= long tedious, expensive
Medical experiment or test preformed on living organism
eg- human being or a laboratory animal
IN VITRO - def
A medical experiment or a study that is preformed only in a laboratory dish or test tube
What does in vitro digestion stimulate?
-Rumen digestion (48hr incubation in rumen fluid at 39 degrees Celsius)
Whats the dacron bag technique of in vitro digestion?
Gastric digestion (48hr incubation in pepsin solution at pH 2)
What does digestion measure ?
The loss of a nutrient (protein, dry matter, NFC, fibre) from dacron bags containing feed when incubated for different times in the rumen
List the two main approaches of assessment feedstuff in an animal?
1- Laboratory assessment
2- Animal assessment
List the 3 main approaches of animal assessment:
3 major approaches are:
* Digestion trial
* Balance trial
* Production (e.g., growth,
lactation) trial
Whats the requirements of a digestion trial?
-individual feeding
-Quantitive faeces collection, separated from urine
-Adequate number of animals >5
-Adequate sampling period >7
-Minimal disruption of feed intake
Whats a balance trial?
Requirements same as for digestion trial, plus measurements of urinary losses
eg- N balance = N intake - (faecal N + urinary N)
Whats the production trial applications?
1- Titrate maximal or optimal responses to:
a) total feed intake
b) intake of specific nutrients
2- Compare the nutritional value of different feed ingredients fed at the same level
What’s the Gain: feed ratio in a production trial feed utilisation ?
average daily weight gain /
average daily dry matter intake
Why isn’t a Lion able to survive on eating plants?
Lions cannot ferment/digest structural carbohydrates
Is a ruminants gi tract sefistated ?
Yes, multiple layers, all of these compartments
What is a carnivores gi tract like?
Small, 1 tube, not complex
Ingestion def
Apprehension of feed, chewing, and swallowing to the initial
digestive organs
Digestion def
– Reduction of food to utilizable form; physical and chemical
processing of ingested food
– Pre‐ingestion processing of feed starts the digestive process
Absorption def
– Active transport
– Passive diffusion
Metabolism def
Post‐absorptive utilization of nutrients
What type of nutrient is protein?
Macronutrient
What is the definition for an essential nutrient?
a substance that must
be obtained in the diet, because the body
either cannot make it or cannot make
adequate amounts of it
What is a definition for the nonessential nutrient?
s one that the body
can make sufficient quantities of it if is lacking
in the diet
What does active transport mean?
Requires energy - ATP
List essential nutrients : (4)
-Essential amino acids (10)
-Essential fatty acids (2)
-Vitamins
-Minerals
Macronutrient definition
is a nutrient that is provided
(not necessarily required) in relatively large
amount in the diet
This is something a body can make
Why isn’t carbs essential in a diet?
Because your body can make it - glyconeyogenicis
List Macronutrients :
– Carbohydrates
– Proteins
– Lipids
– Water
Micronutrients - definition
is a nutrient that is needed in
relatively small amounts in the diet
What’s the largest component of a pigs diet?
Corn
What do carbs make up the highest percentage of who’s diet?
- Animals (farm animals)
List a micronutrient
-Vitamin
-Mineral
The more simple the GI tract is …
The more digestible the diet needs to be
The more complicated the GI tract …
The more complicated the diet cam be, eg- structural carbs
When you think of gastric what do you think of?
stomach, acid
Post gastric fermemtors
The gastric compartment is after the stomach, eg- small intestine
Pre gastric fermenters
-Ruminants , the gastric compartments are before the stomach
Ruminant pre gastric ferment compartments
-Rumen
-reticulum
-omasum
What is the big difference between ruminants and monogastric animals ?
the pre gastric fermentation process
How many caecum’s do chickens have?
2
What do chickens have that grind up their feed?
Gizzard
does the GI tract absorb macronutrients ?
no the GI tract doesn’t absorb macronutrients -
they are too large
this is called digestion
What is lactose structure?
disaccharide
What are carbs broken down into?
Glucose
What are proteins broken down into?
amino acids
what are fats broken down into?
fatty acids
How do animals digest macros ?
They are different and largely depends upon morphology and anatomy
Why can humans only go a few hours without eating
We eat often because we have to generate heat - 2000 cals a day
what animals don’t generate heat?
Snakes, because they dont have to generate heat, they adapt to the heat of their environment
why cant babies goes through the night without eating?
They have a large surface area
Name a bulk feeder?
Snakes
Lish pre gastric fermenters:
-Ruminants (cattle, sheep, deer, camel)
-Non ruminants ( Colobine monkey, Hamster, Kangaroo )
-Hoatzin
List hind gut fermenters / Post gastric fermenters
-Cecal digesters (Capybara, Rabbit, rat, mice)
List hindgut fermenters that have a colonic digesters (sacculated)
Elephant, horse, zebra, new world monkeys , pig, human
List hindgut fermenters that have a colonic digesters (unsacculated)
Panda, dog, cat
Why does a panda eat so much bamboo?
Because they are trying to get nutrients out of it
Do all animals have some fermentative capacity? what is it directly related to?
Yes, its directly related to fibre consumption
What breaks down polysaccharides (forages) ?
bacterial enzymes , these bacterial enzymes are made from microorganisms in the animal
and they go into monosaccharides
what breaks down monosaccharides? (glucose) what’s is broken down into?
Glycolysis broken down into pyruvate (3C)
What is pyruvate (3C) broken down into?
- Acetate (2C)
-Propionate(3C)
What do 2 acetate molecules create?
Butyrate 4C
Whats the small you get from feet?
Its from butyrate
List VFA’s:
Acetate (2C)
Butyrate (4C)
Propionate (3C)
Where does the VFA’s absorbed in your body?
-Rumen
-Colon
What’s the most abundant structural carbohydrate on this planet ?
Cellulose
What’s the two methods for breaking down feed :
-Enzymatic/Chemical digestion
-fermentation digestion
What type of digestion does the ruminant use or the pre gastric fermenter use?
1- Fermentation (Ruminant)
2- Enzymatic (Small Intestine )
3- Fermentation (Large Intestine)
What type of digestion does a monogastric animals have?
1- Enzymatic ( stomach, Small Intestine)
2- Fermentation (Large intestine)
What’s a microbe?
Organic matter
How is ruminants food get digested?
by the micro organisms
carbohydrates are fermented by vfas
How are VFAS absorbed?
Straight through the rumen walls (this is how rumens gets their energy)
What’s the “true stomach” used to digest microorganisms?
This is how ruminants get their protein?
Pre gastric fermenters that are non ruminants , what do they have ?
“Sacculated” stomach
List pre gastric fermenters that have a “sacculated stomach”
Colbine monkey, Hamster, Vole Kangaroo, Hipopatomas, Hoatzin
How many guts do hippopotamus have ?
4 guts
What are the outside of a lobster?
Structural carbohydrates
What is the shells covered with of fish?
Chiton - its fibre
What does the whale eat?
chitinolytic bacteria to digest chiton on the crustacean
So, similar to the ruminant….there’s fermentation but not of cellulose but of chiton
What does sacculated stomachs allow for ?
Fermentation capacity
Does the alpaca stomach have sacculated compartments?
Yes
Name ceacal fermenters? (another name )
Post gastric (hind gut) fermenters
List ceacal digestors:
Capybara Rabbit, Rat, Mice
Where do the fermentation chambers come in hindgut fermentations?
After the “stomach” and the small intestine
They have enlarges hindgut or pouches called “cecae”
Name a Saculated Colon Digeste
Horse
Name a Cecal Digesters
Capybara
Whats important to know about rabbits
Produces two kinds of feces
– One has lots of undigested fiber
– The other is a clearance of caecal contents
(soft, high in microbial content)
* Rabbits eat this to gain microbial
nutrition (primarily protein and vitamins)
Name 2 post gastric fermenter names
a) Cecal Fermenters
b) Colonic fermenters
List animals that are colonic digesters that are sacculated
-Elephant
-Horse
-Zebra
-New world monkey
-Pig
-Human
List animals that are colonic digesters that are unsacculated
-Panda
-Dog
-Cat
What % of a horses GI tract is the LI?
60%
Do all mammals have some fermentative capacity?
Yes some capacity that allows utilisation of ingested fibre
How many litres are in a gallon?
3.78
List adaptions to feed sources
-Prehension
-Mastication
-Deglutition
What is prehension ?
Prehensile adaptations include
forelimb (primates, raccoon),
snout (elephant, tapir), tongue
(anteater, cow), lips (horse,
sheep)
What type of prehension happens in domestic animals?
they use there lips, teeth and tongue
What is Mastication adaptions ?
Masticatory adaptations include
large canines and incisors
(carnivores), specialized molars
(herbivores), relative
toothlessness of edentates
(sloths, armadillos)
What does chewing food increase?
-surface areas and allows enzymes to act on molecules
Whats important to know about Carnivores when chewing?
Carnivores only to reduce the size of the
particle to a size small enough to swallow
Whats important to know about herbivores in the stomach?
Herbivores must chew continuously (40‐
50,000 times a day) to increase surface area
What does mechanical Digestion mean ?
- Physical breakdown of food
begins with the teeth
grinding the food and
increasing its surface area.
An increase surface area
allows for easier chemical
digestion - Bacteria living in the mouth
can feed off of nutrients
sticking to the teeth and
cause tooth decay.
Whats more digestible, meet or plants?
Meet is more digestible ,the SI is smaller than Herbivores
What determines the adaptations in the GI tract?
The diet
What animals have gastric fermentations?
Ruminants
Whats deglutition ?
Deglutition (swallowing) varies
little with diet but quantity and
composition of saliva varies
considerably
Whats functions of digestion?
- Moisten feed (salt and water)
- Lubrication (aids swallowing)
- Starch and (or) lipid digestion (amylase and
(or) lipase): species dependent
How much saliva do different species have?
Amount of secretion
Dogs minimal (lubrication, no enzymes)
Sheep 3‐10 liters/d
Horse 10‐12 liters/d
Cattle 130‐180 liters/d
What does the human stomach act as?
- The stomach acts as a
temporary storage site for
food. Food usually spends
about 4 hours in the
stomach. It has ridges
which allow it to expand to
store about 1.5 litres of
food. - The stomach is also the site
of initial protein digestion
What is Movement in the stomach controlled by?
Sphincters
Whats the partially digested food called in the stomach?
Chyme
Why is SI in mammals shorter than other herbivores or omnivores?
Because meat is more digestible therefore shorter GI tract
Where does the length of GI tract of omnivores fall?
Falls somewhere in the middle
What does pregastric fermentation increase?
Efficiency of fibre digestion
Larger nonruminants offset their digestive inefficiency by eating more
Large quantity of faeces
Whats one of the larger animals on land?
African elephant - eat 200-300kg of grass and trees a day and generate 100kg of faeces
How many times cam panda poop a day?
40
What do small nonruminants do?
Smaller nonruminants select more
digestible forage components and/or
practice coprophagy
What do you need o know about coffee?
Kopi Luwak (animal)
AKA: Civet Coffee
List foregut fermentors :
Bovids
Camelids
Sloths
Colobus monkeys
Kangaroos
Hoatzins
List Hindgut fermentors:
Elephants
Horses
Rabbits
Rodents
Grouse
Iguanas
Some turtles
Whats the vent in poultry ?
Common chamber into which the digestive, urinary, and
reproductive tracts open.
When fecal material is excreted, the vent folds
back allowing the rectal opening of the large
intestine to push out, closing the reproductive tract
opening.
