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Flashcards in Water & protein Deck (50):
1

3 water sources?

Drink, feed, metabolic

2

4 water losses?

Urine (most), faeces, sweat, insensible (breathing/panting)

3

What are the factors affecting water requirements?

Heat production/ambient temp, feed intake, salt, accessibility (sources), water quality, species, physiological state, environmental adaptation

4

What are the steps in assessing water quality?

1. Organoleptic properties (odour & taste); 2. physiochemical properties (pH, salinity, TDS/TSS, TDO, hardness); 3. Toxins (pesticides, heavy metals, toxic minerals); 4. ++minerals, nitrates (urea), sulfates; 5. Bacteria

5

What effects would be seen with TSS <1000?

No risk to stock

6

What effects would be seen with TSS 1000-3000?

Mild diarrhoea possible

7

What effects would be seen with TSS 3000-5000?

Temporary refusal possible

8

What effects would be seen with TSS 5000-10,000?

Not suitable for breeding animals, young stock or poultry

9

What effects would be seen with TSS 10,000-15,000?

Only ok for mature dry sheep & cattle (if accustomed)

10

Proteins are...

the major constituents of all living tissue

11

Protein functions include...?

Immunity (IgGs)
Structural (hair, hoof, wool, horn etc)
Metabolism (enzymes, hormones)
Energy

12

What are the physical properties of proteins determined by?

Amino acids present
Sequence of AAs
Linkages
Non-AA groups

13

10 essential AAs?

Histidine
Isoleucine
Leucine
Lysine
Methionine
Arginine
Phenylalanine
Tryptophan
Threonine
Valine

14

2 protein classes...

Simple - only AAs (fibrous & globular)
Conjugated (contain non-protein groups)

15

Simple protein properties?

Fibrous - resistant to digestive enzymes. Structural role ie. keratins, collagens
Globular - compact folded polypeptide chains ie. albumins (milk, blood, eggs), histones, protamines, globulins

16

Conjugated protein properties?

Chromoproteins (pigmented eg haemoglobin)
Glycoprotein (heteroglycans)
Lipoproteins (lipids)
Phosphoproteins (phosphoric acid eg casein)

17

The other nitrogenous compounds...?

Nucleic acids, amines, amides, nitrates, alkaloids

18

Monogastric protein digestion occurs mainly where?

SI by animals own enzymes (trypsin, chymotrypsin, peptidases)

19

A bit more on monogastric protein digestion...

- Large number of enzymes involved (infinite combo's of 20 AAs)
- Secreted from stomach glands & pancreas as zymogens (inactive)
- Activate in gut lumen

20

Endopeptidases...

Break proteins at internal points along AA chains (produce NO free AAs)

21

Exopeptidases...

Produce free AAs from peptide chain end

22

Zymogen trypsinogen -> trypsin utilises which enzyme?

Enteropeptidase & trypsin

23

Activates chymotrypsinogen

trypsin

24

Activates proelastase

trypsin

25

Activates procarboxypeptidase A

trypsin

26

Activates procarboxypeptidase B

trypsin

27

Step 1 in monogastric protein digestion & absorption:

Dietary & endogenous protein ingested -> hydrolysed by pepsin & pancreatic proteolytic enzymes

28

Step 2 in monogastric protein digestion & absorption:

AAs across apical membrane via Na+/K+ pump

29

Step 3 in monogastric protein digestion & absorption:

Small peptides absorbed by different carrier -> AAs by aminopeptidases or intracellular peptidases

30

What is a limiting AA?

AA that is not present in sufficient amounts -> protein synthesis eg lysine

31

Protein quality refers to..?

AA composition of protein and their availability & biological value (% nitrogen absorbed available for body functions)

32

Ruminant protein digestion involves..?

Rumen modifies digestion via microbes that secrete enzymes -> protein catabolism. Most P's cat. to ammonia or short pep's/AAs & used as N source for microbes

33

What is MCP?

Microbial crude protein - fairly constant AA composition

34

What is UDP?

Undegradable dietary protein

35

Define degradability

Ability of microbe to break protein down

36

Define digestibility

Ability of animal to digest protein

37

Step 1 of rumen nitrogen digestion...

Protein -> peptides via protease enzymes on microbe surface

38

Step 2 of rumen nitrogen digestion...

Peptides ->AAs ->microbial protein synthesis

39

Step 3 of rumen nitrogen digestion...

Another source of AAs from NH3 & VFAs

40

Step 4 of rumen nitrogen digestion...

Some microbes can not use peptides for AA synthesis so use extracellular NH3 for AA synthesis

41

Step 5 of rumen nitrogen digestion...

AAs not used for protein synthesis -> NH3 & VFAs

42

Microbial protein reaches abomasum & SI when?

When microbes are washed out of rumen

43

When is optimal digestive efficiency?

When growth rate of microbial mass is maximal. Depends on nutrient supply.

44

How do most microbes protein -> urea?

Urea cycling (nitrogenous waste products - liver) by endogenous AA deamination & N absorbed as NH3 from rumen

45

Urea in monogastric kidneys...

excreted

46

Urea in ruminant kidneys...

excreted into rumen via blood or saliva

47

T or F ruminants require essential AAs in diet

False - they can synthesise AAs from non-protein sources (urea & NH3/ammonia)

48

Urea = ?% nitrogen

45%

49

T or F - Urea in diet >1% -> toxicity

True -> rapid ++NH3 in blood -> toxic

50

How to avoid urea toxicity?

Introduce slowly, feed at low levels, mix carefully, add carbs & sulphur (cysteine & methionine)