Ruminant Anatomy

Ruminants have 4

Compartments in their stomach

Microbial fermentation

Digests and makes use of high fiber ingredients

Rumination

Regurgitating, Swallow liquid, remastication, resalivation, and reswallowing bolase

True ruminant families

Bovidae, Cervidae, Giraffidae

Mouth

No upper incisor teeth, molars that shred tough plant fibers

Ruminant teeth

Reduce particle size but are not as important as in monogastric because of rumination

Saliva contains

Bicarbonate, few enzymes, and antifoaming to prevent bloat

50% of saliva production comes from

Parotid gland

Why do ruminants have significantly more saliva

Needed for rumination

What elements does ruminant saliva contain

Nitrogen, phosphorus, and sodium that are utilized by microbes

Saliva is highly buffered to

Maintain pH

Why does saliva need to be kept buffered

Fermentation produces acid so buffering helps maintain constant pH

Which part of ruminant stomach is the largest

Rumen

Ruminant stomach in order

Reticulum, rumen, omasum, abomasum

Reticulum

Decides whether or not regurgitation will happen again

Where is reticulum located

Most cranial

Is there enzyme secretion in reticulum?

No

Reticulum is not completely seperated from

Rumen

Reticulum moves undigested feed into

Rumen and omasum

Which structure traps hardware

Reticulum

Rumen

Fermentation vat

Rumen has muscular contractions for

Mixing and moving feed

Why does rumen have papillae

To increase surface area

Rumen function

Physical mixing, breakdown, fermentation, storage, and soaking

A suckling rumen depends on ____ for digestion

Abomasum

In response to suckling, the _______ forms between esophagus and omasum

Reticular groove

Reticular groove

Tube forms from esophagus to omasum that allows milk to escape fermentation

How is reticular groove stimulated

Through suckling

How long does it take for rumen microbial population and fermentation increase

8 Weeks

Does the Reticulum/Rumen or Omasum/Abomasum become larger as calf grows

R/R

Omasum

Muscular laminae studded with papillae

Omasum function

Reduce particle size of digesta and water absorption

Abomasum

True stomach, where real enzymatic digestion takes place

First glandular portion of GI tract

Abomasum

Lysozyme in absomasum

Breaks down bad bacterial cell walls

No microbes in ruminant =

Death

Constant temperature for microbes

102

Constant pH for microbes

5.5-7

What needs to be constantly happening in rumen for microbes

Motility, mixing of digesta through muscle contractions

End products for microbes need to be

Removed, no accumulation

Continuous ______ necessary for microbes at all time

Nutrient supply

Why cant there be any humoral defense mechanisms in the rumen

Since it is filled with microbes, body shouldn’t attack itself

Why do ruminants need to be fed properly

Microbes will die

Microbe that digest cellulose

Cellulolytic

Microbe that digests hemicellulose

Hemicellulolytic

Microbe that digests starch

Amylolytic

Microbe that digests proteins

Proteolytic

What type of microbes digest structural carbs found in feed like hay and fluctuate with diet

Cellulolytic and Hemicellulolytic

What type of microbes utilize mono and disaccharides

Sugar utilizng microbe

What type of microbes utilize succinic and malic acids

Acid utilizing mircobes

What are the two types of producer microbes

Ammonia and methane

What type of microbe is a synthesizer

Vitamin

As long as favorable microbe conditions are met, bacterial synthesis of ___________

Vitamin K and B complex

Microbial protein synthesis

Bacterial synthesis of amino acids and protein

Breakdown of carbohydrates result in release of VFA by bacteria.

Why is this important?

VFA’s serve as a major energy source in ruminant absorbed through rumen

3 acids formed by microbes

Acetic, propionic, and butyric acid

Roughage based diets contain more of which type of acid

Propionate

Propionate acid

Gluconeogenic (creates new glucose)

Acetate and Butyrate acids

Lipogenic, create more fat

Dairy cattle require which type of acid the most

Acetate and Butyrate because they are lipogenic and they require more fat for their milk

Burping is necessary to

Remove gas and prevent bloat

Foregut components and percentage of horse GI tract

Mouth, esophagus, stomach, small intestine (30-40%)

Hindgut components and percentage of horse GI tract

Cecum, large intestine, small colon, rectum (60-70%)

What species have a substantial amount of hindgut dermentation

Horse and rabbits