Ruminants 3

Question 1

What should we typically think about the relationship between protein and nitrogen?

Answer 1

-think of protein as the nitrogen containing portion of the diet
-contrast to carbohydrates and lipids

Question 2

What are the types of proteins?

Answer 2

-true protein
-non-protein nitrogen

Question 3

What do protein contain?

Answer 3

-amino acids
-amino acids contain nitrogen

Question 4

What type of protein is in the rumen?

Answer 4

-dietary protein
-microbial protein
-non-protein hydrogen

Question 5

Ammonia N in the rumen

Answer 5

dietary NPN or protein degradation

Question 6

Where does Urea N in the rumen originate? and where does it come from?

Answer 6

-Originating from the blood
-from the saliva or absorbed through the rumen wall

Question 7

How are dietary proteins classified?

Answer 7

-according to its degradability in the rumen

Question 8

What are the classifications of dietary proteins?

Answer 8

-Rumen degradable protein (RDP)
-Rumen undegradable (RUP)

Question 9

What does degradability determine?

Answer 9

-how microbes interact with proteins
-whether they modify them: Deaminate

Question 10

What does rumen proteolysis by microbes do?

Answer 10

-Proportion of protein is degraded to ammonia N with residual reaching the small intestine intact

Question 11

What are some feeds with high feed protein degradability?

Answer 11

-Soybean meal: 84%
-Cottonseed meal: 60%
-Alfalfa: 83%

Question 12

What are some feeds with low feed protein degradability?

Answer 12

-Blood meal: 31%
-Fish meal: 32%
-Meat meal: 35%

Question 13

What can influence the degradability of protein by microbes in the rumen?

Answer 13

-processing feeds or modifying them
-Heat treating
-Coating or encapsulation

Question 14

What does heat treating do?

Answer 14

Forming crosslinks to limit accessibility

Question 15

What does coating or encapsulation do?

Answer 15

-blockage of access

Question 16

What does reverse modification do?

Answer 16

-limit microbial access in the rumen
-but allow access and digestion in the small intestine

Question 17

Where does reverse modification take place?

Answer 17

-acid reversal happens in the abomasum
-proteolysis by pancreatic enzymes

Question 18

What can overprocessing (overprotection) do?

Answer 18

-limit degradability too much
-not degraded in the rumen or the small intestine

Question 19

What are the two forms protein enter the small intestine?

Answer 19

-feed protein unmodified in the rumen
-microbial protein produced in the rumen

Question 20

Characteristics of microbial protein?

Answer 20

-high quality: good amino acid profile)
-insufficient to support highest levels of production

Question 21

How much of rumen protein do bacteria make up? protozoa?

Answer 21

-bacteria about 50%
-Protozoa vary, but average 40%

Question 22

How much true protein entering the small intestine is microbial protein?

Answer 22

-40%

Question 23

Is microbial protein a significant source of protein for ruminants?

Answer 23

Yes

Question 24

What can many rumen bacteria use to synthesis amino acids?

Answer 24

-Ammonia N

Question 25

When does the ammonia N that rumen bacteria use to make amino acids come from?

Answer 25

-NPN in diet
-Hydrolysis of urea entering the rumen from the animal (nitrogen recycling)
-from protein degradation (deamination)

Question 26

What is Nitrogen recycling?

Answer 26

-Urea converted to Ammonia in rumen
-Urea is from the blood, saliva, or diet

Question 27

How is the nitrogen from nitrogen recycling used?

Answer 27

-excreted in the urine
-some reenters the rumen

Question 28

How is the ammonia that reenters the rumen returned? and used?

Answer 28

-plasma urea crosses the rumen wall or is returned in the saliva
-bacterial urease activity liberates ammonia
-bacteria can use ammonia to produce amino acids and microbial protein

Question 29

When bacteria use ammonia to produce amino acids and microbial protein an energy dependent process?

Answer 29

Yes

Question 30

Is it possible for the flow of protein into the small intestine to exceed the amount of dietary protein fed?

Answer 30

-Yes because you can feed urea and that animal can make protein from it.
-Basically, feed ruminant what it needs to make protein and you get more protein out then was put in

Question 31

What type of protein do ruminants make?

Answer 31

-High quailty

Question 32

Where does NPN come from?

Answer 32

-diet
-from the animal

Question 33

What is the overall process of protein going through a ruminant?

Answer 33

-Protein and NPN enter the rumen
-Some protein degraded to ammonia (RDP): some protein exits the rumen unchanged (RUP)
-Some protein is produced in the rumen from NPN
-Protein entering the small intestine consists of dietary RUP and microbial protein from the rumen

Question 34

What process in the rumen is use to produced amino acids?

Answer 34

-Nitrogen recycling
-use of dietary NPN

Question 35

What are Ionophores?

Answer 35

-modifiers of rumen fermentation

Question 36

What are ionophores originally described as products of?

Answer 36

Streptomyces species

Question 37

What do ionophores do?

Answer 37

-transport cations across membranes
-inhibit the gram positive bacteria in the rumen
-modify the bacteria populations fermentation

Question 38

What is the major function of ionophores?

Answer 38

Improves fermentation products to support greater efficiency
-improved nutrient availability

Question 39

How do ionophores inhibit gram positive bacteria?

Answer 39

-incorporate into cell membrane
-allow flux of ions (loss of gradients)

Question 40

How does ionophores modify the bacteria population fermentation?

Answer 40

-increasing propionate (important to glucose)
-decreasing methane production
-inhibition proteolysis and deamination