Flashcards in Water & protein Deck (50):
3 water sources?
Drink, feed, metabolic
4 water losses?
Urine (most), faeces, sweat, insensible (breathing/panting)
What are the factors affecting water requirements?
Heat production/ambient temp, feed intake, salt, accessibility (sources), water quality, species, physiological state, environmental adaptation
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
What effects would be seen with TSS <1000?
No risk to stock
What effects would be seen with TSS 1000-3000?
Mild diarrhoea possible
What effects would be seen with TSS 3000-5000?
Temporary refusal possible
What effects would be seen with TSS 5000-10,000?
Not suitable for breeding animals, young stock or poultry
What effects would be seen with TSS 10,000-15,000?
Only ok for mature dry sheep & cattle (if accustomed)
the major constituents of all living tissue
Protein functions include...?
Structural (hair, hoof, wool, horn etc)
Metabolism (enzymes, hormones)
What are the physical properties of proteins determined by?
Amino acids present
Sequence of AAs
10 essential AAs?
2 protein classes...
Simple - only AAs (fibrous & globular)
Conjugated (contain non-protein groups)
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
Conjugated protein properties?
Chromoproteins (pigmented eg haemoglobin)
Phosphoproteins (phosphoric acid eg casein)
The other nitrogenous compounds...?
Nucleic acids, amines, amides, nitrates, alkaloids
Monogastric protein digestion occurs mainly where?
SI by animals own enzymes (trypsin, chymotrypsin, peptidases)
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
Break proteins at internal points along AA chains (produce NO free AAs)
Produce free AAs from peptide chain end
Zymogen trypsinogen -> trypsin utilises which enzyme?
Enteropeptidase & trypsin
Activates procarboxypeptidase A
Activates procarboxypeptidase B
Step 1 in monogastric protein digestion & absorption:
Dietary & endogenous protein ingested -> hydrolysed by pepsin & pancreatic proteolytic enzymes
Step 2 in monogastric protein digestion & absorption:
AAs across apical membrane via Na+/K+ pump
Step 3 in monogastric protein digestion & absorption:
Small peptides absorbed by different carrier -> AAs by aminopeptidases or intracellular peptidases
What is a limiting AA?
AA that is not present in sufficient amounts -> protein synthesis eg lysine
Protein quality refers to..?
AA composition of protein and their availability & biological value (% nitrogen absorbed available for body functions)
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
What is MCP?
Microbial crude protein - fairly constant AA composition
What is UDP?
Undegradable dietary protein
Ability of microbe to break protein down
Ability of animal to digest protein
Step 1 of rumen nitrogen digestion...
Protein -> peptides via protease enzymes on microbe surface
Step 2 of rumen nitrogen digestion...
Peptides ->AAs ->microbial protein synthesis
Step 3 of rumen nitrogen digestion...
Another source of AAs from NH3 & VFAs
Step 4 of rumen nitrogen digestion...
Some microbes can not use peptides for AA synthesis so use extracellular NH3 for AA synthesis
Step 5 of rumen nitrogen digestion...
AAs not used for protein synthesis -> NH3 & VFAs
Microbial protein reaches abomasum & SI when?
When microbes are washed out of rumen
When is optimal digestive efficiency?
When growth rate of microbial mass is maximal. Depends on nutrient supply.
How do most microbes protein -> urea?
Urea cycling (nitrogenous waste products - liver) by endogenous AA deamination & N absorbed as NH3 from rumen
Urea in monogastric kidneys...
Urea in ruminant kidneys...
excreted into rumen via blood or saliva
T or F ruminants require essential AAs in diet
False - they can synthesise AAs from non-protein sources (urea & NH3/ammonia)
Urea = ?% nitrogen
T or F - Urea in diet >1% -> toxicity
True -> rapid ++NH3 in blood -> toxic