Transcript AG-ASB-02.421-15.4P Ruminant Digestion T Savelle

Agriscience
August 2008
August 2008
Agriscience
Ruminant Digestion
 Monogastric
 Equine
 Ruminant
August 2008
Agriscience
Mammalian
Digestive Systems
 Humans, pigs, predators
 One compartment
 Glandular design
August 2008
Agriscience
Monogastric
(Simple Stomach)
 Horses and their relatives
 One glandular compartment
 Hind-gut fermenter (cecum) to
digest plants
August 2008
Agriscience
Equine
 Most herbivores
 Four compartment stomach
 Fore-gut fermentation vat to
digest plants
August 2008
Agriscience
Ruminant
Nature’s Amazing
Plant-Digesting Machine
August 2008
Agriscience
The Ruminant
 Chews cud
 40,000-60,000 jaw movements/day
 No upper incisors - dental pad
 Does not “bite” grass - wraps tongue
 Uses fermentation to digest plants
I thought Dumbo
was an elephant
 Symbiotic relationship with bacteria
 Produces 13 gallons of gas/hour
 Produces 40 liters of saliva/day
 Does not sleep!
August 2008
Agriscience
Ruminant Facts (Bovine)
 Rumen - fermentation vat
 Reticulum - rumen’s “assistant”
 Omasum - dehydrator
 Abomasum - glandular stomach
August 2008
Agriscience
Stomach Compartments
 Largest compartment
 On left side of animal
 Contains micro-organisms
 Ferments cellulose
 Absorbs VFA’s
 Divided into chambers
 Continually contracting
 Contains papillae
 Produces CO2 and CH4
 pH close to neutral (6 - 7)
August 2008
Agriscience
Rumen
 Smallest compartment
 Lies close to the heart
 Small sac - part of rumen body
 Catches dense, heavy feed for later
rumination
 Contracts for regurgitation
 “Honeycomb” lining
 Catches hardware and stores it
August 2008
Agriscience
Reticulum
 Third compartment
 Globe-shaped
 Lining called “many plies”
 Reduces feed particle size
 Absorbs water and dries out ingesta
 Absorbs volatile fatty acids
August 2008
Agriscience
Omasum
 Final compartment
 Tubular in design
 “True” stomach (glandular)
 Secretes HCl and enzymes for
chemical digestion
 Reduces pH to 2.5
 Dissolves minerals
 Kills rumen bacteria
 Breaks down proteins
 Passes ingesta to small intestine
August 2008
Agriscience
Abomasum
August 2008
Agriscience
Ruminant Digestion
 Intake
 Mastication (chewing)
 Swallowing
 Regurgitation
 Remastication
 Fermentation
 Eructation
 Absorption
 Digestion
August 2008
Rumination
Agriscience
Ruminant Digestion
 Anaerobic bacteria
break down cellulose
 VFA’s released by
bacteria passed to
bloodstream through
papillae
 CO2 and CH4 produced
by bacteria
 Bacteria controlled by
protozoa
 Ingesta passed to
omasum by contractions
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Agriscience
Fermentation
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Agriscience
Calf Digestive Tract Development
Newborn
 Only abomasum is functional
 Sucking action forms esophageal groove
 Milk passes directly to abomasum
 Milk curdles and digests slowly
 Rumen does not develop as long as calf is on milk
only
Abomasum - 4 liters
Rumen - 1.7 liters
Total Size - 6.7 liters
August 2008
Agriscience
Calf Digestive Tract Development
12-16 Weeks
 Feed (grain) consumption causes rumen to develop
 Rumen is populated with micro-organisms from
environment
 Bacteria produce VFA’s which cause rumen to
develop papillae and increase in size
 Calf can digest hay and grass once rumen develops
Abomasum - 4 liters
Rumen - 13 liters
Total Size - 20 liters
August 2008
Agriscience
Calf Digestive Tract Development
Agriscience Lab
August 2008
Agriscience
Rumen Exploration
 Provides direct access to the rumen
 Possible only in ruminants
 Rumen wall is very close to epidermis
behind the ribs on the left side
 Surgically inserted by a veterinarian
 Not painful or dangerous to the cow
 Permits researchers to:
 Observe rumen function
 Evaluate digestion of different
feedstuffs
 Remove fluid to use as inoculant
for sick cows
August 2008
Agriscience
The Cannula
 Put on obstetrical glove
 Remove cannula lid and permit gas to
exit
 Feel rumen wall and papillae
 Reach into ingesta
 Pick up ingesta (liquid and solid)
 Collect a fluid sample
August 2008
Agriscience
Rumen Investigation and
Sampling
The Rumen Contains:
 Bacteria (digest cellulose)
 Over 200 species
 Smaller than 5 microns (5/1000 mm)
 Can only be seen with an electron microscope
 Protozoa (control bacteria population)
 Much larger (20-200 microns)
 Can be seen with microscope at 400X
 Prey on bacteria
 Fungi (aid in cellulose digestion)
 Same size range as protozoa
 Numbers are very low in rumen
 Discovered only 20 years ago
August 2008
Agriscience
Rumen Fluid Evaluation
 Place a drop of fluid on a slide
 Position cover slip
 Place under microscope
 Locate fluid smear at low power
 Increase to 400X and adjust light
August 2008
Agriscience
Rumen Fluid Evaluation
Rumen Microorganisms
Dasytrich and Entodinium protozoa
Large protozoa
Isotrich and Entodinium protozoa
Fungal sporangia
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Agreement
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To Comply With Unapproved and Extra-label Drug Use Rules
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Of the Georgia Junior Livestock Program
By signing this agreement I acknowledge and agree to the following:
I am a bona fide member of the Morgan County FFA Chapter.
I understand that the Georgia Department of Agriculture may conduct random urine drug tests on all species at the
livestock shows beginning in 2004.
I have read and/or had explained to me the rules regarding unapproved and extra-label drug use in animals
participating in the Georgia Junior Livestock Program and agree to abide by the following:
I agree not to give a show animal any medication not specifically labeled for it according to its species, age, time to
slaughter, or stage of lactation.
I agree not to exceed labeled dosages when giving animals over-the-counter medication or medication prescribed by
a veterinarian.
I agree not to give a show animal prescription medication unless that animal is under the care of a licensed
veterinarian.
If I have an animal under the care of a veterinarian and am administering medication according to the veterinarian’s
instructions I agree to have the prescription in my possession while my animal is on the premises of a show. I
understand that a prescription does not necessarily mean that my show animal is automatically in compliance with
the rules if a urine test reveals a specific violation.
I agree to abide by withdrawal times of medications and/or feed additives. I will not bring an animal to a show that
is within the withdrawal window stated on the medication and/or feed additive’s label.
I agree to notify Mr. Savelle of any medications that my show animal is receiving as soon as I begin administering
the medication.
I understand that violation of the rules on unapproved and extra-label drug use in animals that I exhibit in the Georgia
Junior Livestock Program may result in fines, disbarment from exhibiting livestock at junior shows in the future, and
possible legal action against myself, my parents, and my agriculture teacher.
I have participated in a class offered by my FFA chapter in which I was made aware of the rules governing
unapproved or extra-label drug use by the Georgia Junior Livestock Program.
Signature of Student
Date:
Signature of Parent/Guardian
Signature of Agriculture Teacher/FFA Advisor
August 2008
Agriscience
August 2008