Exam 3 – Dr. Fleming Ruminant Physiology 1 Flashcards
What is a ruminant?
Any even-toed, hoofed animal of the suborder ruminate, being comprised of cloven-hoofed, cud chewing quadrupeds, and including, besides domestic cattle, bison, buffalo, deer, antelopes, giraffes, comes, and chevrotains
What are ruminants able to do?
Utilize forages other animals cannot digest
What are the forestomachs of ruminants?
Rumen
Reticulum
Omasum
Abomasum
What do the esophageal and reticulo-omasal groove do?
Help bypass the rumen in young ruminants
Describe the special feature of ruminants in the mouth
No upper incisors or canine teeth
Dental pad
Which animals are high fiber, indiscriminate ruminants?
Cattle
Which animals are low fiber, discriminate/browser ruminants?
Sheep and goats
What is the size of the large intestine of ruminants?
33 ft
7.5 gal
What is the size of the cecum of ruminants?
3 ft
2.5 gal
What is the size of the small intestine of ruminants?
150 ft
16 gal
What is the size of the abomasum of ruminants?
5 gal
What is the size of the rumen of ruminants?
42.5 gal
What is the size of the omasum of ruminants?
4 gal
What is the size of the reticulum of ruminants?
2.5 gal
What are the advantages of being a ruminant?
Break down cellulose
Allows synthesis of high biological value protein
Production of all B vitamins
What are the disadvantages of being a ruminant?
Regular food intake at regular intervals
Long hours chewing
Keep rumen fermentation vat balanced
How long does a ruminant spend on food ingestion?
4-7 hours/day
How long does a ruminant spend chewing cud?
8 hours/day
What keeps the rumen fermentation vat balanced?
Large quantities of alkaline saliva
Constant mixing
Release of gasproducts
What are the rumen layers?
Gas
Fiber mat/raft
Fluid slurry
What is the diet of ruminants?
Roughages (cellulolytic)
Legumes (cellulolytic)
Grains (Amylolytic)
What are the different roughages?
Cellulose (glucose)
Hemicellulose (xylose)
Pectin (galactose)
What are legumes able to do?
Fix nitrogen
What are the different grains?
Starches
Simple sugars
What are requirements of fermentation?
Regular addition of fresh food Presence of suitable microbes Steady removal of end products Continuous mixing Propulsion of fine particles and fluid Anaerobic Stability of temperature, osmotic pressure, redox, and pH
Describe protozoa
Live in fiber mat Very sensitive to change Feed on bacteria, plant starch and PUFAs Provide high biological value protein Prefer pH of 6.2
What pH does cellulolytic bacteria prefer?
6.2
What pH does amylolytic bacteria prefer?
5.8
Describe lactobacillus spp.
Takes over at pH less than 5.8
Lactic acid producing
What is the normal rumen pH?
5.5 - 7.0
What pH is there with acute acidosis/grain overload?
Less than 5
What pH is there with acute subacute acidosis/SARA?
Less than 5.5
What are are diamond fistulas used for?
Rumen transfaunation
What are the products of fermentation?
Gases
VFAs
Microbial and protozoal protein and lipids
Ammonia
What gas is produced from fermentation?
Methane
What happens to VFAs from fermentation?
Absorbed across rumen wall
What happens to microbial and protozoal protein and lipids from fermentation?
Passed through to abomasum
What happens to ammonia from fermentation?
Absorbed across rumen wall
What are examples of VFAs?
Acetate
Butyrate
Propionate
What are the ketone bodies?
Acetone
Acetoacetate
Beta-hydroxybutyrate
Describe acetic acid
Minimal liver use
Oxidized throughout most of the body
Major source of Acetyl CoA for synthesis of lipids
Describe propionic acid
Major liver use
Serves as a major substrate for gluconeogenesis
Critical because almost no glucose reaches small intestine for absorption
Describe butyric acid
Comes out of the rumen as the ketone beta-hydroxybutyrate
Oxidized in many tissues for energy production
What kind of diets produce more acetate and butyrate?
High fiber diets
What kind of diets produce more propionate?
High grain diets
What is protein broken down to in ruminants?
Simplest for–ammonia
How much gas is produced?
Up to 40 L/hour 2-4 hours after a meal
What are the green house gases?
Water vapor Carbon dioxide Methane Nitrous oxide Ozone
What percentage of green house gases is methane?
7.9%
What does rumination do?
Mixes rumen fermentation vat continuously
Filters fluid and particulate matter through to omasum an abomasum
What does rumination allow for?
Regular release of gas – eructation
Cud chewing
What does cud chewing do?
Reduces particle size and increases saliva flow
Describe the parasympathetic innervations of forestomachs
Vagus nerve
Promotes rumination and cud chewing
Describe the sympathetic innervations of forestomachs
Thoracic ganglia to celiac
Decreases motility
What happens to nervous cows?
Drip/drool saliva
Decrease rumen contractions
What are the types of rumen contraction?
Primary – mixing
Primary – cud chewing
Secondary – eructation
Primary and secondary – cud chewing with eructation
