Lecture 6 Flashcards
Ruminant Maxillary Incisor Teeth
Absent in ruminants.
Depend on dental pad, lower incisors, lips & tongue for prehension.
Molars shaped for one-sided chewing.
Ruminant Lateral Jaw Movements
Aid in shredding tough plant fibers.
Saliva production in ruminants
Continuous
Functions similarly to non-ruminants.
Increased quantities during eating/ruminating
Composition of Saliva
Source of nitrogen, phosphorus, sodium.
Highly buffered for rumen microorganisms.
Production Volume of Saliva
Cows: 150L or more daily.
Sheep: 10L or more daily.
Major Modifications of Ruminant Stomach
One stomach, four compartments.
Reticulum, Rumen, Omasum, Abomasum.
Compartments in Pseudo-Ruminants
No omasum (Camels, others).
Size Comparison of Ruminant Stomach
Cattle stomach: 37% of GIT, 25% of total BW.
Holds up to 55 gallons.
Epithelium in First 3 Compartments
Squamous epithelium, 1-2 cells thick.
Allows absorption.
Pre-Gastric Fermentation
60-70% fermented before typical digestion.
The reticulum is the
First Compartment
Honeycomb-like luminal surface.
Traps sharp objects, may cause hardware disease.
Functions of Reticulum
Moves ingested food.
Assists in regurgitation.
The rumen is the
Second Compartment
-Largest, lined with papillae.
-Strong muscular pillars for mixing and regurgitation.
The omasum is the
Third Compartment
-Spherical shape.
-Side leaves prevent large particles from entering the abomasum.
The Abomasum is the
Fourth Compartment
-Comparable to glandular stomach of non-ruminants.
The Reticular Groove
In Young Nursing Ruminants
-Forms a tube from esophagus to omasum.
-Allows milk to escape bacterial fermentation.
Rumination is basically a controlled form of vomiting
Forms bolus in reticulum.
Re-swallows liquid portion.
Re-masticates solid bolus.
Duration of Rumination
8 hrs/day or more.
Stimulated by fibrous diets.
Eruction or Belching of Gas
Result of microbial fermentation.
Prevents bloat.
Rumen Fermentation - Carbohydrates
Composition of Herbivore Diet
Mostly fibrous and available carbs.
Ruminal Acidosis
Result of abnormal fermentation of cereal grains.
High lactic acid production.
Rumen Fermentation - Proteins
Attack on Dietary Proteins
Degraded to ammonia and organic acids.
Utilized by other rumen microbes.
Protein sources for ruminants
Urea, amino acids, nitrates, biuret, amines.
Lower-cost alternatives.
Consumption of lipids (ruminants)
Low, added at 5-7% of the total diet.
Usually unsaturated.
Microbial Tolerance of Lipids
Intolerance to high dietary fat levels.
Results in abnormal fermentation.
Rumen Fermentation - Vitamins: B-complex Synthesis
Microorganisms synthesize B-complex vitamins.
Cobalamin (B12) deficiency if low in cobalt.
Rumen Fermentation - Vitamins: Thiamin (B1) Deficiency
High RAC diet may cause deficiency.
B12 & B1 deficiency with high RAC diets.
Rumen Fermentation - Gas Production
Up to 600L/day in cattle.
CO2, CH4, N, O2, H2, H2S.
Methane production in Ruminants
High heat equivalent, direct energy loss.
Produced during fermentation.
Digestive Tract of Non-ruminant Herbivores
Extensive fermentation in hindgut.
No chambered stomach.
What animals have a sacculated colon
Equids, new world monkeys, pigs, humans.
What animals have a unsacculated colon
Fruit-eating bats, dogs, cats.
What animals are cecal fermenters
Rodents, rabbits, capybara.
Microbial Digestion in Colon is not as efficient as in ruminants when digesting fibers.
Fermentation of fiber into VFAs.
Important for meeting nutritional requirements.
