Nutrition exam #3

What are the end products of ruminal fermentation of starch and what happens to these products?

VFA: absorbed and used as energy

MCP, CH4, and CO2: excreted

Describe the location of starch digestion in the ruminant. What proportion of starch is digested in each of these locations?

Rumen: 75-80%

Small intestine: 15-20%

Large intestine: 5-10%

Name the most common structural carb consumed by ruminant animals.

Cellulose

What buffers are present in ruminant saliva?

Bicarbonate and phosphate

At what rumen pH is cellulose digestion optimized?

6.5

What is fungi’s role in structural carb metabolism?

Assist by breaking down cell wall

Amino acids are linked by what type of bonds?

Peptide bonds

What is the difference between an essential amino acid and a non-essential amino acid?

Essential amino acids are not synthesized by animal tissues and therefore are needed in the diet.

Non-essential amino acids are synthesized by animal tissues and therefore are not needed in the diet.

What are all of the nutritionally essential amino acids?

Phenylalanine

Valine

Threonine

Methionine

Arginine

Tryptophan

Histidine

Isoleucine

Lysine

What is crude protein?

True protein + non-protein nitrogen (total amount of protein)

What is non-protein nitrogen?

Inorganic nitrogen salts, amino nitrogen, amides, etc.

What is degradable intake protein (DIP)?

Protein that can be degraded by rumen microbes

What is undegradable intake protein (UIP)?

Protein that cannot be degraded by rumen microbes

What are the most common amylolytic and dextrinolytic bacterial species in the rumen?

Bacteroides amylophilus

Streptococcus bovis

Succinimonas amylolytica

Succinivibrio dextrinosolvens

What are the ruminal enzymes most common in non-structural carb digestion?

Amylase

Glucoamylase

Pullulanase

Isomaltase

What are the most common cellulolytic bacteria in the rumen?

Bacteroides succinogenes

Ruminococcus albus

Ruminococcus flavefaciens

What are the cellulase complexes?

Glucanases (exoglucanase and endoglucanase)

Cellobiohydralase

Cellobiosidase

Cellodextrinase

What are the stages of rumen development in the young ruminant?

0-3 Weeks: non-ruminant phase

3-8 Weeks: transitional phase

>8 Weeks: adult ruminant

What are the bacteria present in the large intestine in a monogastric?

Bacteroides succinogenes

Ruminococcus albus

Ruminococcus flavefaciens

What are the cellulase complexes present in the large intestine of monogasrics?

Glucanases

Cellobiohydralase

Cellobiosidase

Cellodextrinase

Where is HCl produced?

Parietal cells

Where is pepsinogen produced?

Chief cells

What triggers the release of pepsinogen and HCl?

Vagal stimulation and gastrin.

What is the purpose of HCl?

To denature proteins and activate pepsinogen into pepsin.

Through which two main routes does blood plasma urea enter the rumen for nitrogen recycling?

Saliva and rumen wall