L7: Water and Protein Flashcards Preview

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Flashcards in L7: Water and Protein Deck (25)
1

*Describe the factors affecting water requirements

 

  • Heat production/ambient temperature
  • Feed intake
    -quality and type
  • Salt
    -level
  • Accessibility to water source
    -travel distance
  • Water quality
    -turbidity, salt etc
  • Species
  • Physiological state
  • Environmental adaptation

2

Define essential amino acid and list examples    

An essential aa must be obtained from the diet as it cannot be synthesised by the body.

10 classed as essential

  • Arginine
  • Histidine
  • Iso-Leucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

3

List some:
water sources?

water losses?

  • Sources:
    - drinking
    - feeding
    - metabolic water
  • Losses:
    - urine
    - faeces
    - sweat
    - insensible; no solutes (skin, respiratory tract)

4

What range of % is the animals body made of water?

50 - 80%

5

Which is the most critical nutrient?

WATER

6

*Describe measures of water quality

How do we assess water quality?

  • Odour and taste (organoleptic properties)
    -bad smell = high microbial popn
  • pH, salinity, TDS/TSS (total solutes in solution), TDO and hardness (physiochemical properties
  • Organic chemical contaminants, heavy metals, toxic materials
  • Excess minerals, nitrates, sulfates
  • Bacteria
    - coliform in faeces

7

*Describe measures of water quality
Describe TSS (ppm) levels and their suitability

  • TSS = TOTAL SOLUTES in SOLUTION
  • <1000
    - no risk to stock
  • 1000 - 3000
    - mild diarrhoea possible
  • 3000 - 5000
    -temporary refusal possible
  • 5000 - 10,000
    - avoid using for breeding, poultry, young stock
  • 10,000 - 15,000
    -okay for mature dry sheep/cattle
  • Greater than 15,000 mg/L TSS or > 600mg/L Mg = unsuitable for stock

8

 

Are proteins essential? Why?

What is their function?

  • Yes, essential. Must be provided in diet as true protein or NPN
  • Major constituents of all living tissue
  • Can be made but deplete quickly

9

Describe protein structure

  • Chains of amino acids
  • Physical properties determined by sequence and type of aa present, presence of non-aa groups
  • Aa's all contain N, have amino group, carboxylic acid group and side chain


     

10

Amino acid groups:
name characteristics of:
Non-polar = 
Polar =
Acidic =
Basic =

??
 

  • Non-polar = hydrophobic
  • Polar = hydrophilic (non-charged)
  • Acidic = -vely charged
  • Basic = +vely charged

11

 

What are the two types of protein classes?

  • Simple (only amino acids)
  • Conjugated (contain non protein groups)

12

Describe simple proteins

  • only aa
  • Fibrous (resisitant to digestive enzymes). Structural roke e.g. collagens
  • Globular (compact, folded polypep. chains) e.g. albumins (milk, blood, eggs, plants)

13

 

Describe conjugated proteins

  • Glycoproteins (contain heteroglycans)
  • Lipoproteins (contain lipids)
  • Phosphoproteins (contain phosphoric acid)
    - e.g. casein; rumen protected protein
  • Chromoproteins (contain pigments) e.g. haemoglobin

14

Describe some examples of Non Protein Nitrogen (NPN)

  • Nucleic acids
    - building blocks of all living organisms
    -contain purines, pyrimidines, a pentose, phoshoric acid
  • Amines
    -involved in DNA, RNA, protein synth, cell signalling, can be toxic
  • Amides
    - urea and uric acid
  • Nitrates (N3)
    -can be reduced to nitrite (N2) in rumen -highly toxic
  • Alkaloids

15

*Describe the process of protein digestion and absorption in monogastrics and ruminants 

Monogastrics.

Protein digestion mainly occurs where?

Describe Liebig's law of minimum (limiting amino acid)

  • digestion of proteins occurs in sml intestine
  • Growth is controlled not by total amount of resoirces available but by scarcest resource (Liebigs law)
    - deficient in 1 aa effects production of others
  • most important aa in diet is one w/ least [ ]
  • Limiting amino acid is any aa not present in sufficient amounts to enable protein synthesis to proceed

16

*Describe the process of protein digestion and absorption in monogastrics and ruminants 

Describe monogastric protein enzymes

  • Secreted from stomach glands or pancreas in form of zymogens (inactive form)
  • Activated in lumen
  • ENDOpeptidases:
    - break proteins at internal points along aa chains
    -produce essentially NO FREE aa's
    -small chunks of part protein
  • EXOpeptidases:
    -release individual aa's from ends of peptide chains
    -free floating aa's

17

*Describe the process of protein digestion and absorption in monogastrics and ruminants

Describe the membranous-phase of digestion of proteins in MNG

  • Digestion of peptides occurs in SI
    -surface membrane
    -w/in the cells
  • Peptidases present of enterocyte surface
    -breakdown protein to yeild free aa
    -absorbed locally
  • Some longer chain peptides incompletely digested
  • Absorbed di and tri peptides hydrolysed by intracellular peptidases
    -free aa's enter blood

18

*Describe the process of protein digestion and absorption in monogastrics and ruminants

Monogastric diagram

Draw as much as you can, describe as much as you can

19

Describe protein quality and biological value (BV)

  • Protein quality
    -refers to aa composition of protein and their availability
  • BV
    -% of N that is available for body functions
    -proportion of N that is retained by the body

20

*Describe the process of protein digestion and absorption in monogastrics and ruminants

What is microbial crude protein (MCP)?

  • MCP is the protein produced in the microbes
    -main source of protein for host
  • MCP eventually digested by animals own enzymes
  • 40% true protein; 80-90% digested in SI

21

*Describe the process of protein digestion and absorption in monogastrics and ruminants

List ruminant protein sources

22

*Describe the process of protein digestion and absorption in monogastrics and ruminants

Describe microbial protein production

  • most dietary protein degraded in rumen
  • MP reaches abomasum & SI when microbes washed out of rumen
  • Optimal digestive efficiency occurs when growth rate of microbial mass is maximal
  • Need rapidly growing microbe popn
    -dependent on nutrient supply
     

23

*Describe the process of protein digestion and absorption in monogastrics and ruminants

Describe the synthesis of microbial protein from NPN

  • If sufficient energy, microbes can synthesise protein from NH3
  • NH3 converted into urea in liver (recycling process; MNG do not do this they excrete via kidneys)
  • Recycling in saliva or returned to rumen as NPN source
     

24

How much urea should you feed as a NON source during drought?

  • Do not feed more than 1% of total diet as urea
  • e.g. if feeding 2.5kg diet/day use no more than 25g

25