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AS 408
Ruminant Nutrition
80
Agriculture
Undergraduate 4
02/05/2012

Additional Agriculture Flashcards

 


 

Cards

Term
What are the Advantages of Ruminants?
Definition

1. Harvest forages from unproductive land

2. Synthesis of vitamins (B,K) by microbes

3. Convert NPN to proteins by microbes

4. Eat a lot of food in a short time

Term
What are the Disadvantages of Ruminants?
Definition

1. Large GI tract

2. Degrade proteins in rumen

3. Metabolic disorders from high grain diets (DA, ketosis, acidosis)

Term
Identifying a Ruminant
Definition
1. GI tract anatomy
2. Teeth for grinding
3. Cud chewing
4. Blood composition: lower glucose, higher VFAs, enzyme differences, fat melting point
Term
Organization of Ruminants
Definition
Kingdom: Animal (solid food, mvmt)
Phylum: Chordata (vertebrate), Craniata (head)
Class: Mammalia
Subclass: Ungulata (hooves)
Order: Artiodactyla (even toed hooves)
Suborder: Ruminatia
Family: Bovidae, Cervidae, Giraffidae
Term
What are the Prehensile Organs?
Definition
  • Lips, tongue, lower incisor teeth, dental pads
  • Determine what an animal eats
Term
Tongue
Definition
  • Grazers (cattle): plump & piston-like
  • Browsers (sheep): slender & pointed
Function: formation of boluses, papillae, taste buds
Term
Teeth
Definition

Only one set in a lifetime

Move bilaterally - side to side

Fully developed in cattle (2-3 yrs) and sheep (4 yrs)

Cattle have 32 teeth

Term
Esophagus
Definition

1. Regulates pressure, reverse peristalsis, drives regurgitation

2. Movement in both directions constantly

3. Sphincters @ top and bottom

4. Esophageal Groove: shunts milk to abomasum

Term
Saliva
Definition
  • Enzyme: only lipase from nasolabial gland
  • Buffers: control pH of rumen for bacterial environment
  • Lubrication, bolus formation, and transportation
  • Mastication causes release of saliva
Term
What are the four "stomachs?"
Definition

Reticulum, Rumen, Omasum: nonglandular epithelium

- Store food, delay passage, absorb water & VFAs

- No secretion

Abomasum: glandular epithelium

Term
RUMEN
Definition

Lined with papillae that are dense in ventral sac & lower rumen because that is where absorption takes place.

Larger papillae w/ forage diet, smaller w/ grain diet.

Papillae growth stimulated by butyrate.

Term

Function of:

1. Omasum

2. Abomasum

Definition

Omasum: Water Absorption

Abomasum: glandular structure w/ parietal cells that secretes HCl for protein digestion (gastric acid)

Term
Small Intestine
Definition

- All parts have villi, each villus has a lacteal
Duodenum
: scretion of pancreatic enzymes, mixing, little absorption, brings pH up with bicarbonate secretion

Jejunum

Ileum

Term
Large Intestine
Definition

- No digestion or enzymatic secretions

- Cecum: microbes (microbial protein), B vitamins, & VFA's absorbed

* Microbial protein does not contribute to protein because no gastric acid to break down

 - Water and electrolyte absorption & storage

- Methane (CH4) & CO2 absorbed into bloodstream & expired

Term
Types of Colon
Definition

Spiral: muscles squeeze in a spiral - sheep - pelleted feces

Flaccid: feces form pies (cows)

Term
Liver
Definition

- Lobulated, undivided gland

Function: detoxification & modificatio of blood, synthesis of bile, metabolizes CHO/fat/protein, stores vitamins (fat soluble)

- Blood enters through portal vein, exits through hepatic vein

- Detoxifies by attaching an H20 soluble molecule

- Modifies blood by adding/synthesizing albumin, which metabolizes lipids

Term
Pancreas
Definition

Endocrine: insulin (anabolic, Islet cells) & glucagon (catabolic)

Exocrine: enzymes

- Lobulated gland

- Function: digestive enzymes, electrolytes, hormones

Term
What are the five paired glands?
Definition
Parotid, Submaxillary, Inferior Molar, Sublingual, and Buccal
Term

What are the three unpaired glands?

 

And the one lone gland?

Definition

Palatine, Pharyngeal, Labial 

 

Nasolabial Gland

Term
What are the three types of saliva?
Definition

1. Serous

2. Mucous

3. Mixed

Term
Serous Saliva
Definition
  • Alkagenic: buffers the acid in the rumen
  • Thin & watery, makes rumen "liquid"
  • Continuous flow, not stimulated 
* Parotid, Inferior Molar, Palatine
Term
Mucous Saliva
Definition
  • Mucogenic, thick
  • Glycoproteins: protein source for microbes
  • Function: ease of swallowing, lubrication
  • Stimulated by eating
* Buccal & Pharyngeal Glands
Term
Mixed Saliva
Definition
  • Some serous, some mucous
  • Induced secretions
* Submaxillary, Sublingual, Labial, Nasolabial
Term
Functions of Saliva
Definition
  1. Lubrication/Moistening of Feed (increases density, moves through rumen)
  2. Mastication
  3. Buffering Capacity (rumen microflora, bicarbonate & phosphates)
  4. Recycling of Nitrogen (urea in saliva, important for survival in low quality feed)
  5. Maintain rumen fluid
  6. Palatability
  7. Lipase Activity (Nasolabial gland)
  8. Antibodies (IgG's, IgE's, plasma = isotonic with saliva)
  9. Nutrients for microbes (urea, glycoproteins, P, Mg
  10. Bloat Prevention (saliva = antifrothing, no emulsion - no gas cap)
Term
Composition of Saliva
Definition

1 % Dry Matter

Na+, K+, Ca2+, Bicarb, HPO42-, Cl-, N, S

pH: 8.1 - 8.4 (Forage Ruminant: 6.8 - 6.2)

Cattle: 150 L/day (50 gal)

Sheep: 6-10 L/day (4.2 gal)

Term
Amount of Saliva Depends On...
Definition

Feed type, palatability, activity (eating, ruminating, resting)

 

* Longer eating time - more chewing - more saliva

* Feed forage first - more saliva

Term
Ruminal Motility Function
Definition

MIXING

- Aids in attachment of microbes to feedstuffs (by exposure)

- Movement to the omasum

- Rumination

- Regurgitation

- Eructation

Term
Types of Contractions
Definition

Primary: mixing

- Reticulum becomes 1/2 normal size

- Feedstuffs floating on top are pushed down, dense particles sink

Secondary: eructation (30 s)

- Most methane & gases expired via lungs

Term
Regurgitation
Definition

Reticulorumen contracts, cardia flooded w/ fluid & particles, animal takes a deep breath, increased pressure in thorax, cardia opens, reverse peristalsis occurs.

Rechews bolus w/ molars.

Increases SA of particles, removes air pockets, increases density, causes to sink in rumen

Term
Omasum Contractions
Definition

Slow, prolonged contractions

Feedstuffs leave omasum independent of the body.

Term
Abomasum Contractions
Definition
- Control everything
- Every 4-6 minutes, mixes pepsin and feedstuffs, initiates digestion
- Distension causes release of contents into SI, antral pumps tell abomasum when to empty
- pH of chyme = 2
Feeding Frequency: 1x (270 ml/hr), 3x (785 ml/hr)
Term
Intestinal Contractions
Definition
1. Segmental Waves (8-10 minutes)
- Mixing of content with enzymes; goes down with milk diet, increases with hay
2. Peristaltic Contractions
- Propelling (precede segmentals)
Term
Gram Positive Bacteria
Definition
- Stain dark blue
- DO NOT have a lipopolysaccharide layer
- Peptidoglycan outer layer
Term
Gram Negative Bacteria
Definition
- Stain red
- Have a lipopolysaccharide layer
Term
Anaerobic vs. Facultative vs. Obligate Bacteria
Definition
Anaerobic: very low oxygen
Facultative: can withstand small amounts
Obligate: will die if it sees oxygen (ex: protozoa)
Term
Rumen Ecosystem
Definition
1. Open & Continuous (input & output, constantly being refreshed)
2. Saccroclastic Fermentation (CHO breakdown)
3. Redox Potential is NEGATIVE (-250 to -40 mV). Reduced atm, double bonds quickly saturated.
Term
Rumen Ecosystem
- Temp?
- pH?
- DM?
- Gas Composition?
Definition
Temperature = 38-42 C
pH = 6.0-7.0 (6.8 = normal)
DM: 10-18% dorsal sac (bigger, top of fiber mat)
6-9% ventral sac (higher density, highly liquid)
Gas Comp: 65% CO2, 27% CH4, 7% N2, 0.6% O2, 0.01% H2S, 0.2%H2
Term
Why do we care about hydrogen sulfide (H2S) gas concentration in rumen?
Definition
Distillers products have high sulfur content. Animals can get polioencephamalacia (sulfur toxicity).
Term
What are the inhabitants of the rumen?
Definition

1. Bacteria (1010-1011/mL)

Obligate & Facultative Anaerobes

3/4 bound, 1/4 free

2. Protozoa (105-106/mL): obligate anaerobes

3. Fungi (107/mL): strict anaerobes

4. Mycoplasma (105-107/mL)

5. Bacteriophage (107/mL)

Term
Rumen Bacteria
Definition
  • 200 different species, highly conserved, different concentrations
  • Ciliated, flagellated
  • Wide variety of substrates (starch, bacteria)
  • Classify based on substrate used
  • Can use multiple substrates
Term
Ruminal Fungi
- Substrate?
- % of Biomass?
Definition
Anaerobic, obligate
Highly cellulytic (higher than bacteria)
8% of ruminal biomass
Eat cellulose, hemicellulose, xylans, starch, pectins
Term
What happens when protozoa is removed from the rumen?
Definition
  • No protozoal nitrogen
  • Decrease in methane production
  • Decrease in fiber digestion
  • Decrease in ruminal insoluble protein digestion
  • Increase in biohydrogenation (dbl bond to single bonds)
  • Increase in ruminal starch digestion
  • Increased Cu absorption 
  • Changes in bacteria & fungi conc.
  • Change in rate of passage
    * Bacteria eat dead protozoa!
Term
What are the factors that affect microbial growth?
Definition

1. Energy Source: C - ATP, protein & FA synthesis

2. Nitrogen: bacteria, protozoa, fungi use NH3

3. Minerals

4. Vitamins

Term
What are the common microminerals? Macrominerals?
Definition

Microminerals: P, K, Mg, Fe, Ca

- Mg = limiting for microbes

Macrominerals: Mn, Co, Mb

 

* Cofactors for enzymatic reactions!

Term
What vitamins are needed for microbial growth?
Definition
  • Biotin, PABA - hoof health
  • Coenzyme M - methane synthesis
  • Hemins, cytochromes - used for transport
  • Branch chain VFA's - for synthesis of branch chain amino acids
  • Phenylpropionic Acid - byproduct of fiber digestion, one cellulose helps another
  • Aromatic Amino Acids - ring structure cannot be synthesized in rumen (Tyrosine, Phenylalanine, Tryptophan)
Term
Types of Relationships in Rumen
Definition

Competitive: for nitrogen, protozoa eating bacteria, bacteriophages, fungal infections, bacteriocins

Beneficial: use of breakdown products

Ex: cellulose - cellulodextrins - cellobiose - glucose; puts intermediates back into rumen for further breakdown

 

Term
Methanogens
Definition

Attached to protozoa (rumensin)

Inside the protozoa (hydrogenosome)

Free Floating

Term

Electron Sinks

 

Definition
  1. Biohydrogenation
  2. Propionate: longer chain, more hydrogen. Feed more starch/glucose, decrease methane production.
  3. Oxaloacetate, Malate (see glycolysis) - need slow release
  4. CH4 - waste of energy, contributes to greenhouse gases
Term

Factors That Affect Microbial Balance

1-5

Definition
  1. Diet - microbes adjust to balance chemical & physical nature of feed
  2. Plant species & soil fertility (minerals, N, alkaloids)
  3. Climate
  4. Eating Behavior
  5. Physiological Status - pregnant, stressed. Increased salivation, ROP. Higher liquid conc. from saliva increases ROP. Extreme cold - increase ROP - more opportunitiy to eat (energy)
Term

Factors that affect microbial balance

(6-10)

Definition
6. Geographic Location
7. Metabolites produced in the rumen
8. Condition in the rumen
9. State of adaptation - diet changes
Ok to shift 100% forage to 50/50 forage/grain, but need to slowly introduce grain past this to prevent bloat. 
10. Growth Rate

 

Term
What does the bacterial growth rate curve look like?
Definition
[image]
Term

RUMEN DEVELOPMENT. 

go. 

Definition
Suckling calf causes closing of esophageal groove. Abomasum not function for first 24 hrs, important for absorption of antibodies. Some milk goes to rumen, ferments, creates VFA's (butyrate), stimulates rumen growth. Innoculation from mom's saliva, vagina, licking, teats, etc. Have to get protozoa from another animal. Takes 3-4 wks to get adult microbial pop. Musculature requires solid feed.
Term

Process: 

Salivary Output

 

Outcome?

Definition
Buffering, liquid in rumen, lubrication, density increase, dilution/flow out, antibodies, nutrients
Term

Process: 

Rumination

 

Output?

Definition
Breakdown of feed, more saliva, increase density (wet, no air pockets, smaller particles)
Term

Process: 

Rumen Movement

 

Outcome?

Definition
Eructation of gas cap, emptying of rumen, mixing, regurgitation, sequestration
Term

Process: 

Gas Production

 

Outcome?

Definition
Eructation (prevent bloat), surface tension, and removal of CH4 for pH maintenance
Term

Process:

Absorption Through Wall

 

Outcome?

Definition
Removal of end products, pH (VFA's disappearing), NH3
Term
What makes up the cell wall of a plant and why is it not easily digestible?
Definition

Pectin, cellulose, hemicellulose, lignin. 

Lignin = indigestible, everything is all mixed up with lignin so accessibility is reduced. 

Term
Pectin
Definition

Rhamnogalacturonic Acid

Found in middle lamella

Cements the cell walls together 

Highly digestible

Made of galacturonic acid, arabinose, and galactose
Term
Hemicellulose
Definition

Xylans, glucans, mannans, arabinozylans, and arabinogalactans

Flexibility of cell wall

Grasses: higher content

Legumes: lower content (Alfalfa = 10%)

Highly digestible

Term
Cellulose
Definition

Beta-1,4 linked glucose

H2 bonds

Synthesized continuously 

Important for rigidity

Crystalline and amorphous types have different digestibilities

Term
Lignin
Definition

Hydroxycinnamic Acids

High in mature plants

Primarily in legumes

Considered indigestible

Term

Silica

Waxes

Definition

Silica: cements lignin, usually nonentity but can be a problem

Waxes, chlorophyl: nutrients

Term
General Breakdown Pathway of Complex Polysaccharides (hemicellulose, cellulose, etc)
Definition
Complex Polysaccharide -> Oligosaccharides -> Oligomers -> Dimers -> Monomers (glucose) -> VFA's
Term
What are the enzymes used in the breakdown of cellulose?
Definition

Enzyme 1 = Beta 1,4-gluconase(endo); high molecular weight polymers

Enzyme 2 = cellobiohydrase; breaks down cellopentoses, cellotrioses, cellobioses

Enzyme 3 = Beta-glucosidase; breaks down cellobioses

Enzyme 4 = cellobiosidases; converts to glucose

* Glucose production stimulates Beta-1,4-Gluconase

Term
Starch
- What enzyme breaks down starch?
Definition
Amylose & Amylopectin
Enzyme: amylase
Term

Hemicellulose

- Digestibility?

- Associations?

- Higher in grasses or legumes?

Definition

100% digestible, but not in naturally occuring forages

Complex Molecule

Closely associated with lignin - low digestibility

High in grasses, low in legumes

Term
What are the two methods of forage analysis? When would you use each?
Definition
Near Infared Reflectance & Wet Chemistry Analysis
NIR determines composition based on light chemistry...cheaper!
Wet chemistry is good for unusual feedstuffs that the lab won't have a calibration for.
Term
  • What are the components of the cell wall? 
  • Label on a forage analysis?
  • Digestibility?
Definition
  • Cellulose, hemicellulose, pectin, heat damaged protein
  • Neutral Detergent Fiber
  • 20-80%
Term
  • What are the components of ADF?
  • Digestibility?
  • Why is the digestibility different from NDF?
Definition
  • Cellulose, lignin, heat damaged protein
  • 50-90%
  • Higher digestibility becuase it is more impacted by the amount of heat damaged protein
Term
What is the digestibility of acid detergent lignin?
Definition
0%!!!
Term
What are the components of the cell solubles? Digestibility?
Definition

Starch, fat, soluble protein, NPN, sugars, pectins

 

95-100%

Term

Starch Digestion:

  • Molecular Pathway?
  • Steps?
Definition
  • Starch → Dextrins  → Maltoses  → Glucose
  1. Attachment of Bacteria: depends on access (barley vs. corn)
  2. Secrete endo and exo enzymes that break α1-4,  α1-6 bonds in amylose & amylopectin
Term
Where does the glucose formed in starch digestion go?
Definition
Glucose goes to the TCA cycle where it is converted to propionate predominantly.
Term
What are the ways to change the digestibility of grains? How do they work?
Definition
  1. Heat: makes grain more soluble. ex: steam roll
  2. Use Moisture. Ex: high moisture corn
  3. Time in rumen
  4. Mechanical Action: grinding, cracking, rolling. 
  5. Use a blend of grains (barley, corn, and wheat) to create a continuum of digestion.

↑ SA, ↑ Rate of Passage, ↑ Digestibility

Also! Sheep are good at chewing. Do not need to process grains.

Term
What are negative assortative effects? When did we discuss them in class?
Definition
Negative assortative effects occur when adding more starch decreases starch digestibility. Depression of the starch population results in ↑ RoP, smaller particles (starch=soluble) sink and go through faster.
Term
What is the breakdown of energy? (Hint: start with Gross Energy)
Definition
Gross Energy à(fecal) Digestible Energy à (urine, gas) Metabolizable Energyà Net Energy
Term

How many hours after feeding does peak VFA production occur? 

 

What does the pH look like at this point?

Definition

4 hours

 

pH is almost at it's peak (most basic)

Term
How does VFA absorption take place? (Broad)
Definition
  • Absorbed across the ruminal papillae (which increase SA)
  • Concentration dependent passive diffusion
  • Blood flows by & has a lower concentration of VFA's, so they cross from rumen to blood. 
  • More absorption in lower pH because the VFA's can pass directly, without having to wait to be converted to an acid. (Have to be in acid form to cross epithelium)
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