Docstoc

Energy - No Slide Title

Document Sample
Energy - No Slide Title Powered By Docstoc
					ENERGY

2 Systems
  TDN
 Calories
GROSS ENERGY
GROSS ENERGY
               Feces
  GROSS ENERGY
                 Feces
DIGESTIBLE ENERGY
  GROSS ENERGY
                 Feces
DIGESTIBLE ENERGY
                 Urine & Gas
    GROSS ENERGY
                   Feces
 DIGESTIBLE ENERGY
                   Urine & Gas
METABOLIZABLE ENERGY
    GROSS ENERGY
                    Feces
 DIGESTIBLE ENERGY
                    Urine & Gas
METABOLIZABLE ENERGY
                   Heat increment
    GROSS ENERGY
                    Feces
 DIGESTIBLE ENERGY
                    Urine & Gas
METABOLIZABLE ENERGY
                   Heat increment
     NET ENERGY
              GROSS ENERGY
                                Feces
           DIGESTIBLE ENERGY
                                Urine & Gas
        METABOLIZABLE ENERGY
                               Heat increment
               NET ENERGY


Maintenance Gain Reproduction Milk Production
Gross Energy includes all the energy in a feed.
   •It is not all available to the animal
   •It is determined by how much heat is liberated upon
   combustion.

Digestible Energy is how much energy does not end up
in the feces.
    •Therefore it was absorbed.
    •It is not all used by the animal, some is lost.

Metabolizable Energy is what is left after accounting for
energy in feces, urine and gasses.
   •It is still not all available for the animal to use.
                Net Energy
• Is what is left after accounting for losses to
  feces, urine & gasses and heat increment.
  – Heat increment is energy lost in fermentation
    and in metabolic processes.
• Net Energy is available for the animal to
  use.
• It is not used with the same efficiency for
  all processes.
• Net Energy is always used most efficiently
  for maintenance.
• Milk production is almost as efficient as
  maintenance.
• Gain (growth and fattening) is less efficient.
• Different uses for energy require different
  values be used for the energy content of
  feeds for each purpose.
• Maintenance needs must always be met first
• This complicates ration balancing.
              GROSS ENERGY
                                Feces
           DIGESTIBLE ENERGY
                                Urine & Gas
        METABOLIZABLE ENERGY
                               Heat increment
               NET ENERGY


Maintenance Gain Reproduction Milk Production
   Determining Caloric Energy
• Use Paar Adiabatic
  Bomb Calorimeter
     Steps in determining calories
•   Prepare sample (grind, pellet, place in bomb)
•   Wire bomb and charge with Oxygen
•   Place in calorimeter in known amount of H2O
•   Measure initial temperature
•   Ignite
•   Measure final temperature
                Calculations
• 1 calorie = energy to raise 1 g H2O 1° C
• 1000 cal = 1 Kcal
  – (In humans 1 Calorie = 1 Kcal, animal
    nutritionists don’t use Calorie vs calorie)
• Temp rise X g H2O = calories in sample
• Cal in sample X amount of feed = Cal in
  feed
  – same for feces
• Calculate the total calories (or Kcal) (per
  day) eaten and excreted (in feces, urine).
• Calculate DE, ME, Net E (must know the
  endogenous contribution in Kcal/Kg and %
  – For Kcal/Kg divide the Kcal of interest by Kg
    consumed
  – For %, divide the Kcal of interest by Kcal of
    feed consumed (times 100).
                     TDN
• Total Digestible Nutrients
  – Forget that, I consider it a misnomer
  – It is really:
• An ENERGY INDEX on a carbohydrate
  equivalent basis
• Calculated from proximate analysis
            Calculating TDN
•   % CP X Digestibility    =      x
•   % EE X 2.25 X Digestibility = x
•   % CF X Digestibility        =x
•   % NFE X Digestibility       =x
•                               ------
•   SUM = TDN                     TDN
                    Example
•   Water              12
•   Nitrogen           2
•   Ether Extract       4
•   Crude Fiber        10
•   Ash                  2
•   NFE
                  Example
•   Water               12
•   Nitrogen 2 (2*6.25) 12.5
•   Ether Extract        4
•   Crude Fiber         10
•   Ash                  2
•   NFE
                  Example
•   Water               12
•   Nitrogen 2 (2*6.25) 12.5
•   Ether Extract        4
•   Crude Fiber         10
•   Ash                  2
•   NFE                 59.5
                  Example
                               digestibility

•   Water               12
•   Nitrogen 2 (2*6.25) 12.5    .80
•   Ether Extract        4      .75
•   Crude Fiber         10      .40
•   Ash                  2
•   NFE                 59.5    .80
                     Example
                                      digestibility

•   Water                 12
•   Nitrogen 2 (2*6.25) 12.5            .80 = 10
•   Ether Extract           4 * 2.25 * .75 =6.75
•   Crude Fiber            10           .40 = 4
•   Ash                      2
•   NFE                   59.5          .80 = 47.6
       •                               -----------------
• TOTAL (TDN)                          68.35

				
DOCUMENT INFO
Shared By:
Categories:
Stats:
views:139
posted:8/13/2010
language:English
pages:25