Chapter 6- Ruminants Flashcards
What are cattle called?
Bos Taurus
Bos Indicus
what is a Giraffe
They are ruminants, they are interesting in what they eat, they eat the leaves (least amount of structural carbohydrates) off the top of the tree instead of the grass (structure)
What are ruminants characterised by?
4 compartments of their stomach and also their cud chewing behaviour.
How many species of ruminants?
15 species
-Cows, goats, deer, buffalo, bison, moose,
elk
Name the 3 major classes of herbivores?
-concentrate selectors (deer, giraffes)
-intermediate feeders (Sheep Moose, Goats)
-roughage grazers (buffalo, cattle, camels)
List advantages of ruminants (pre-gastric fermenters)
-Can eat the worlds most abundant organic molecule (cellulose)
-Escape predators (eat, run, masticate later)
-Detoxification of secondary plant substances (Allows greater latitude in dietary choice and adaption)
-Relieved the animal of requiring external source of B-Vitamins and amino acids. (Rumen microbes synthesis B-vitamins and high quality protein.
What’s the real differences of the ruminants and monogastrics?
pre gastric fermenters compartments.
What’s the rate of passage in ruminants and what % of cellulose is utilised ?
-80 hours
-60% cellulose utilisation
How much saliva is produced by the cow every day?
200 litres of saliva
(55 gallons) produced by the cow
What is in saliva? and what’s its purpose?
Rich in :
Na+, K+, HPO4-, acts as an important buffer against rumen acids
Production of hydrogen does what to pH?
more hydrogen= pH goes down
What is the function of saliva?
-Provides 70% of water in the rumen
-Source of salivary lipase that acts on short chain fatty acids (no amylase)
-Contains urea for N recycling
Bicarbonate and phosphate buffering
-Bloat presentation
Why will you never get wine more than 14%?
The bugs are making ethanol, now the ethanol content of the wine will kills the bugs so that’s why its never more than 14%
Why would people burn alcohol in the olden days ?
because it would burn if it was concentrated
if you have a cow how do they keep the pH correct?
They have buffers in their saliva
if you have whiskey how do they ferment it?
% of alcohol is high= its distilled
What’s the reflex of a ruminant?
“Chewing its cud”
-postprandial regurgitation of
partly digested feed from the
reticulorumen.
-Allows leisurely physical breakdown
of fibrous feeds long after initial, hasty
consumption.
How many hours a day do cows chew?
How many chews a day?
- 9/10-11 hours a day
-30,000 chews a day
it reduces the particle length and increases the surface area , it stimulates saliva production
What does ruminant chewing do?
-reduces particle size, only small particles pass from the rumen.
-Chewing= saliva production
-Increase surface area for microbial
production.
-Breaks down waxes and other compounds on the plant surface that cant be digested
-Stimulate saliva production.
Whats the pH inside the rumen?
5.5-7
Whats the temp of the rumen?
39 degrees Celsius
What’s the % of DM in the rumen?
10-15%
(Hydrogen producing reactions that happen in the rumen)
What does 1 glucose convert into?
2 pyruvate + 4H
(Hydrogen producing reactions that happen in the rumen)
What does 1 pyruvate convert into?
2 acetate + CO2 + 2H
What are included in the rumen fibre mat?
-Entry = oesophagus
-gasses in
-fibrous mat
-liquid phase
-reticuolo-omoasal orifice (exit)
Whats the scientific name for burping?
eruacatition
What is erucatation?
Removal of fermentation gasses from the rumen (CH4, CO2, NH4, N2)
Stimulates by distension of the reticulum and rumen
Failure to eructate results in bloat (High pressure build-up of gasses)
What % of the total tract capacity is fermentative? in -Cows
-Humans
-Dogs
-83%
-17%
-14%
What function do calves use ?
- Oesophageal groove
Whats the function of the rumen?
Have pippli to increase surface area and for absorption.
-Fermentation, storage, physical mixing and breaking down.
-Contains obligate anaerobic microbes
-Absorption of VFA’s (acetate. protonate. butyrate) - passive diffusion
What is an obligate anaerobiate ?
Cannot have air
How much bacteria is in the rumen?
25-50 billion bacteria/ml (highly specialised)
Things to know about rumen::::
Fermentation takes cellulose converts it into glucose and uses 4 atp and now it is conserved into one of the 3 vfas that the animal conserves
How much microorganisms are in :
1- oral cavity
2- stomach
3- jejunum
4- rectum
5- rumen
1- 10^12
2- 10^3
3- 10^5
4- 10^11
5- 10^12
Why do we floss?
cause the microbes wont have anything to ferment
Explain rumen metabolism:
-Large fermentation chamber in front of gastric part of GIT
-Dietary components are eaten (fermented) by microbes (bacteria and protozoa)
-Most of diet is converted to microbial waste
products (VFA’s) which are absorbed by rumen
wall
-Anaerobic environment (little or no oxygen)
-Little or no carbohydrates reach the small
intestine
Whats the rumen size of a cow?
1500lb
Whats the rumen size of a ewe?
150lb
Where is the rumen located ?
left side of abdomen
In the rumen whats it lined with?
Papillae
-Highly vascular - it aids in absorption
-Increases surface area
-Absorption of VFA’s (passive diffusion)
Whats the central intermediate in microbial fermentation:
glucose
-cellulose by cellulases in cellulolytic
bacteria, fungi
-starch digestion by amylases in
amylolytic, protozoa
What do rumen microbes do to feed?
rumen microbes degrade feed and produce:
CO2 CH4
VFA
Degradable Rumen Microbial cells
Feed microbes NH3
Heat
Long-chain
fatty acids
H2 S
“Waste” Products”^
What’s inside a microbe
3 macro nutrients
-fat
-protein
-vitamins b and k
What does the reticulm look like?
-Looks like honey comb
-main function: mixing and regurgitation
-no enzymes, just microbes
-Digesta can pass back and
forth freely from the rumen
to the reticulum (often
called reticulo-rumen)
-No clear distinction
between rumen and
reticulum
What does reticulum form?
Bolus
regurgitation initiates here
it collect hardware (nails , wire)
What type of a lining is an omasum ?
Laminae/manyply lining
– Muscular folds
– No secretions
-Reduces particle size
-Absorption of water
~60% removed
-Absorption of VFAs
– ~2/3 of VFAs entering or
10% of total produced
– Prevents buffering of the
abomasum
Whats the anatomy of an omasum?
– Laminae/manyply/leaves lining
– No secretions
-Last opportunity to absorb the vfas ( we don’t wanna buffer the abomasum)
What’s the abomasum of a rumen?
- True, glandular stomach, secretes HCl, pepsin, etc.
-Smooth surface
-3 regions:
(1- cardiac, 2- Fundic, 3- Pyloric)
pH decreases from 6-2.5
denatures proteins (unfolding it) (egg whites)
-Kills most bacteria and pathogens
-Dissolves minerals
-Gastric digestion
- Functions similarly to monogastric
stomach - But-secretes gastric lysozyme (enzyme that efficiently breaks down bacterial walls)
Whats the digestible secretions of Abomasum:
Digestive secretions
* HCL
* Pepsinogen
* Rennin (Chymosin): made by chief cells
Does the stomach kill 100% of bacteria?
nope that’s why we get food poisoning sometimes
What does digestion tend to do with the increase of passage rate?
Digestion tends to decrease with increasing passage rate
List the factors that affect digestibility :
– plant maturity, feed processing, other
feeds in the diet, type of microbes
Why is saliva so important?
Hydrogen being produced that reduces pH, microbes die , digestion stops, hydrogen is being produced because of the breakdown of cellulose, hemicellulose, through glycolysis this produces hydrogen. The reason its so important for cows to generate saliva in rumination the saliva produces buffer, this ensures pH is stable and microbes can do their work.
What is passage rate
amount of time a feedstuff enters the feed tract ad the amount of time it takes to be released.
What factors affect digestibility?
– plant maturity, feed processing, other
feeds in the diet, type of microbes
What does passage mean?
– the flow (speed) of
undigested residues through the
digestive tract
What does passage rate depend on?
- Rate depends on particle size and
density - Rate increases with increasing feed
intake - Retention time affects extent of digestion
- Animal size, level of production, environment
affect intake, which affects rate of passage
Does large, dry particle pass slowly or quickly in passage rate?
- Large, dry particles do not pass as quickly as
small moist particles
Tell me about the orf
The orfus is up near the reticulum , Its small hole and in order for it to be passed through the digestion tract food particles need to be smaller. If an animal is eating large particles, the rate of digestion goes down and passage rate goes down as it needs to be smaller to get through the orf
Name the 2 competing processes?
Digestion and Passage
(Rumen microbes)
How many different bacterial species are there with 25 concentrations of >10^7 cells/ml
200 different bacterial species
what does food intake do when the weather gets hot?
It goes down
List the different rumen microbes :
- Protozoa
- Fungi
- Each species has
its own niche and
requirements(has its own function)
How many microbes are accounted for when it comes to bacteria?(what%)
60-90%
-Almost exclusively anaerobic
-Highly digestible by the enzymes made y the hosts. The amino acids that are inside the microbes are exactly what the animals need, components include protein and lipids
List bacteria’s:
- Cellulolytic ( digest cellulose)
- Hemicellulolytic (digest hemicellulose)
- Amylolytic (digest starch)
- Proteolytic (digest proteins)
Need to know these ones ^^^ - Sugar utilizing (utilize monosaccharides and
disaccharides) - Acid utilizing (utilize such substrates as lactic,
succinic and malic acids) - Ammonia producers
- Vitamin synthesizers
- Methane producers
What is the process of anaerobic fermentation?
Cellulolytic bacteria and Amylotic bacteria are out into the process of glycolysis=
-Glucose is broken down into 2- 5 ATP (Acetic acid, Propionic acid, Butyric acid)
What % does protozoa bacteria account for of the total microbial mass? what size is it and is it fast?
- Account for 20-40% of total microbial
mass - Relatively large size
- Relatively slow turnover
When lambs and calves are deprived from ruminal protozoa what happens?
Depressed growth rates and relative “poor-doers”
What does protein utilise ?
In general, protozoa utilize the same set of substrates as
bacteria and, as with bacteria, different populations of
protozoa show distinctive substrate preferences. Many
utilize simple sugars and some store ingested
carbohydrate as glycogen
An additional feature of protozoa is that many species
consume bacteria, which is thought to perhaps play a role
in limiting bacterial overgrowth
How many years have we known about fungi? and tell me more about it :
-35 Years
* Number usually low (5-10% of microbial
mass)
* Digest fiber
* Exact role is not certain
What is an important aspect of ruminant metabolism
Nitrogen recycling
In order for my microbe to provide what are the 2 things it needs ?
ATP and Nitrogen
-NH3 is important N source for cellulolytic
bacteria
-Amino acids and small peptides are important
for amylolytic bacteria
Whats an important end product of protein and mom-protein nitrogen (N)
Ammonia
what do Ruminants provide the following
to the microbes:
– Guaranteed housing with a reliable heating
system
– Adequate nutrition
* Feed and water
– Buffered neutral environment
– Waste (including gas) removal
What are short chain fatty acids?
same as VFA’S
where are VFA’s absorbed in ruminants?
- Short chain fatty acids (acetate,
propionate and butyrate) are absorbed
and provide energy to the host.
– VFAs, not glucose, provide most energy - Eructation (burping) of CO2 and CH 4
– 30-80 liters/day - Passage of indigestible feed residue and
microbes to the hindgut
What is monogastric and ruminants primary fuel?
Monogastric animals-primary fuel we use to generate ATP
Ruminants-primary fuel= VFA’s(acetic, protonic and butyrate)
What do microbes provide the host with? (2)
– Digestion of cellulose and hemicellulose
* All cellulases are of microbial origin
– This results in the production of VFA’s
What do the microbes provide for the host?
-Provision of high quality protein (appropriate
amino acid balance) to yield 50 - 80% of the N
required by the ruminant
-Detoxification of poisonous compounds
-Supply of B and C and K-Vitamins
What % of N is from microbes?
50-80%
What will increase microbial efficiency provide?
Increased microbial efficiency will
provide more microbial protein
and reduce feed costs
What is the characteristics of an ideal rumen fermentation ?
- Rapid rates of fiber digestion
- Optimal ratios of fermentation acids
- Efficient microbes
– Maximize amount of microbial protein per unit of feed - Rapid microbial growth
– Lactating cow can produce 2.7 kg of microbial protein/day - Slow rate of protein fermentation and minimal NH 3
accumulation - Protection from toxic substances
If you taje a microbe and chemically evaluate it what would you find?
Highly digestible:
almost half of it is protein and Nitrogen digestibility
What do rumen microbes synthesis?
- Rumen microbes synthesize B vitamins
and vitamins C and K
– Usually in excess of animal requirements
– Sometimes in early lactation, supplementation
is beneficial
Why do rabbits eat their own poop?
they eat it because there are 4 nutrients
microbial protein, vit B,C,K
