-
Importance of water
- Highest requirement of all nutrients
- Can lose 100% of body fat, 50% of protein and still live, but lose 10% of body water and deal with dehydration and poosibly death
- Body water = 70-75% of fat-free body mass
-
6 Functions of water
- 1. Transport - digesta and nutrients and metabolites
- 2. Excretion of waste
- 3. Cell rigidity and elasticity
- 4. Lubrication and cushioning
- 5. Biochemical reactions
- 6. Maintenence of body temp
-
Consume
- 2-4 times more water then dry matter
- water restrictions limit feed intake
-
3 sources of water
- Drinking (60%)
- Eating (30%)
- Metabolic (10%)
-
Relative proportion of water depends on:
- Species
- Metabolic, physical state
- Water supply
- Diet type
-
Water requirements increase with
- Dietary protein and salt
- Lactation
- Increases in temp
- High dry matter intake
- High fibre levels
-
Greatest to least production of water in metabolic intake
- Fat, starch, then protein
- Depends on amount of H in feed
-
Desert animals
survive by not sweating, reducing respiration rate, oil on surface to reduce water loss, stay underground during the day, urine very concentrated (camels->fat metabolism)
-
Water loss
Urine, feces, lungs (respration), skin surface (evaporation), milk and eggs
-
TDS
- Total Dissolved Solids
- -crude measure of water quality by measuring mineral content
- Increased TDS thend to decrease water intake
- Poultry very sensitive to water quality, cattle least sensitive
-
Water contaminants
- SO4-2 (sulfate), if >1000ppm catharitc effect
- NaCl (if high in H2O, reduce it in the feed)
- NO2- (nitrite) - oidizes iron in hemoglobin
- >10ppm, unacceptable for humans
- pigs can tolerate <300 ppm
- cattle tolerate < 1000pp
- NO3 (nitrate) Less toxic then nitrite, but bacteria can turn it into nitrite
-
DEB
Dietary Electrolyte Balance
-
Electrolytes
Dissolve in water and dissociate into ions, water follows these ions
|
|
