Ruminant Nutrition

What are the 3 steps in obtaining nutrition in ruminants?

Ingestion, digestion, and absorption

What is ingestion?

Taking food into the body

What is digestion?

The mechanical and chemical breakdown of food

What is absorption?

Passage of nutrients from the digestive tract to the bloodstream

What are two important aspects of a ruminants oral anatomy (not including teeth)?

The prehensile tongue and dental pad

What are the 4 mechanical factors of digestion?

Mastication, Deglutition, Rumination, and Eructation

What is Mastication?

The grinding of roughage and concentrate

What is deglutition?

The swallowing of partially ground cud

What is Rumination?

The chewing of cud that occurs in 4 phases

What is Eructation?

The elimination of CO2 and CH4 from the GI tract

What are the 4 phases of rumination?

Regurgitation, remastication, reinsalivation, and redeglutition

What is regurgitation?

Reentry of cud, the liquid portion from reticulum to mouth

What is remastication?

The regrinding of the cud

What is reinsalivation?

The additional salivary secretion to the bolus

What is redeglutition?

The reswallowing of the bolus from the mouth into the esophagus

What ruminants ingest?

Forages such as grass/alfalfa and silage, and concentrates such as non-forage nutrient sources

What parts of the ruminant digestive system are in charge of fermentative digestion?

The rumen, reticulum, omasum, and large intestines

What parts of the ruminant digestive system are in charge of enzymatic digestion?

The abomasum and small intestines

True or False: Ruminant digestion is the same as microbial digestion.

True

The Rumen is broken down into 3 phases, what is the first top part of the rumen?

Gaseous phase

The Rumen is broken down into 3 phases, what is the second middle part of the rumen?

Liquid phase

The Rumen is broken down into 3 phases, what is the last bottom part of the rumen?

Solid phase

What are the 5 primary nutrients?

Protein, carbohydrates, fats, water, and vitamins/minerals

Protein requirements vary depending on what?

Animal weight and level of production (growth, reproduction, and lactation)

Crude Protein (CP is the quantity of what?

Nitrogen

True or False: CP indicates if a feed will satisfy an animal’s protein needs and is NOT actual protein.

True

Rumen microbes synthesize what?

Microbial protein from all nitrogen-containing substances ingested

How much of CP intake should be natrual protein?

2/3

No more than what amount of CP should be non-protein?

1/3

Non-protein nitrogen (NPN) should not constitute more than what percent of the diet?

2%

Ruminant nutrition requirements are met by what?

Microbes

Bacteria contains what percent of protein?

65%

More than what percent of ruminants utilize ammonia as a nitrogen source for growth?

80%

Structural carbohydrates are fermented by what?

Microorganisms

What is an example of a structural carbohydrate and what are examples of that example?

Fiber - cellulose, hemi-cellulose, and pectin

Non-structural carbohydrates are digested by what?

Enzymes

What is an example of a non-structural carbohydrate and what are examples of that example?

Concentrates - sugars and starches

What breaks down fatty acids?

Rumen bacteria

True or False: Ruminants consume a predictable quantity of dry matter per day when feed is readily available.

True

On average, cattle eat what percent of their bodyweight in dry matter each day?

2-3%

What is neutral detergent fiber (NDF)?

Measures total plant fiber

What are the components of a total plant cell wall?

Cellulose, hemicellulose, and lignin

Is an increase in NDF an increase or decrease in DM intake?

Decrease

What is a neutral detergent soluble (NDS)?

Measures plant cell contents such as CP, sugars, starches, and organic acids

What is acid detergent fiber (ADF)?

Measures indigestible parts of a plant

What are the indigestible parts of a plant?

Cellulose and lignin

Is an increase of ADF an increase or a decrease of energy and digestibility?

Decrease

What is total digestible nutrients (TDN)?

Measure of digestible components

Is the higher the percent of TDN, the higher or lower the digestibility?

Higher

What is gross energy (GE)?

Total energy released through oxidation

What id digestible energy (DE)?

GE minus energy lost in feces

What is metabolizable energy (ME)?

DE minus energy lost in urine and methane gas

True or False: Ruminants have a minimum energy value requirement.

True

What does Pearson square ration balancing show? What does it provide?

The proportion of two feeds to be mixed. Provides percentage of needed nutrient