Ruminal Protein

Question 1

Can animals be fed a diet adequate in protein but still be deficient in some amino acids?

Answer 1

Yes it is possible

Question 2

How are amino acids classified?

Answer 2

by their R group

Question 3

Structure of amino acid

Answer 3

Amine (-NH3)
Carboxyl (-COO)
R group

Question 4

What makes an amino acid essential? Non-essential?

Answer 4

Essential: cannot be produced in sufficient quantities to meet needs
Non-essential: can be produced sufficiently

Question 5

Which amino acids are essential?

Answer 5

Phenylalanine
Valine
*Threonine
*Tryptophan
Isoleucine
Methionine
Histidine
*Arginine
Leucine
Lysine

Question 6

What 3 maintenance functions are amino acids needed for?

Answer 6

1. Endogenous urinary N (amino acid pool)
2. Replace scurf
3. Replace metabolic fecal N.

Question 7

What is scurf? What is metabolic fecal nitrogen?

Answer 7

Scurf = proteins lost from body surface
Metabolic fecal N = proteins lost from undigested digestive secretions (enzymes/mucus) and fecal bacteria

Question 8

What animals require the most CP?

Answer 8

Calves and lactating dairy cows

Question 9

What is the most ideal amino acid source for ruminants?

Answer 9

“true” protein

Question 10

What are some examples of true protein?

Answer 10

proteins, peptides

Question 11

What are some examples of non-protein nitrogen?

Answer 11

Urea, ammonia, nitrates, nitrites

Question 12

Urea is __% N

Answer 12

44%

Question 13

What is the difference between RDP and RUP?

Answer 13

RDP: used by microbes (incorporated into cell or deaminated)
RUP: escapes rumen bacterial degradation

Question 14

What factors affect microbial CP degradation?

Answer 14

1. stage of plant growth (mature less degradable)
2. cross linking of peptide chains
3. Seed coat
4. Chemical nature of proteins
5. Rumen pH
6. Heat
7. mineral chelation

Question 15

How does 3 dimensional structure of a protein affect degradability?

Answer 15

differences in solubility and how well it unravels

Question 16

Isoelectric point

Answer 16

pH where proteins are least soluble

Question 17

How does heat affect protein degradability?

Answer 17

1. reduce trypsin inhibitors
2. increase escape
3. maillard reaction of aldehyde with NH2 of protein

Question 18

How does source of carbohydrate effect ruminal amino acid fermentation?

Question 19

What is the fate of ammonia produced in the rumen?

Answer 19

1. Eructated
2. Made into urea by the liver

Question 20

What is the fate of ammonia after it is absorbed?

Answer 20

1. makes amino acids that go into the blood pool

Question 21

What is nitrogen recycling and what is the benefit for ruminants?

Answer 21

ammonia recycled back to rumen
Benefit is it serves as N for microbes when protein consumption is limited

Question 22

When would it be beneficial to supplement dairy or beef cattle with RUP and/or protected amino acids?

Answer 22

may be beneficial for calves or dairy cows