energy systems Flashcards
what are the 3 main components of energy and protein systems
what the animal needs
what the feed provides
formulate these together
what 2 pieces of information do protein systems bring together
amino acid requirements of animal
available amino acids from diets
different between digestible energy and metabolizable energy
urine and methane removed to calculate metabolizable energy
difference between gross energy and digestible energy
faeces removed to calculate digestible energy
difference between metabolizable energy and net energy
heat increment
how is gross energy calculated
using bomb calorimeter
formulation for digestibility
feed intake less faeces output all over feed intake
why is the energy digestibility higher than the DM digestibility
because DM digestibility contains components such as vitamins that have no energy
as intake increases losses in faeces increases but will losses to methane/urine increase or decrease
losses to urine/methane decrease
list the 2 ways heat increment is measured
- animal calorimeters
- indirect calorimetry
how does indirect calorimetry work
estimate heat production from oxygen consumed, carbon dioxide produced and from nitrogen in the urine
what is needed to carry out indirect calorimetry
respiration chamber
what are the 2 types of respiration chambers
1 open circuit
2. closed circuit
respiration chambers account for all energy lost than left with the net energy
what is the approach when measuring the NE using comparative slaughter
measure the amount of energy retained by animal rather than measure all the losses
why would comparative feeding trail be used
to identify the best feeds to use when fattening
name the 3 ways energy is used during HI and rank them in order of most efficient
- maintenance
- milk production
- fattening
what are the 4 factors affecting the ME value
- digestibility
- species
- type of digestion occuring
- food preparation
what is the reason for different ME values in same food stuffs between monogastric and ruminants
ruminants account for methane losses
if metabolisability is 0.4 was is the ME value
7.4 MJ/kg DM
if metabolisability is 0.5 what is the ME value
9.2 MJ/kg DM
if metabolisability is 0.6 what is the ME value
11.0 MJ/kg DM
if the metabolisability is 0.7 what is the ME value
12.9 MJ/kg DM
what is the GE estimated to be in the AFRC system
18.4
what are the 2 biggest factors affecting the efficiency of utilisation
quality of the feed
purpose of the feed
what is metabolisability
ME content expressed as proportion of GE content of the feed
what are the DM, CF, CP EE and OMD values of the standard barely used in the UFL system
DM = 87%
CF = 4.36 %
CP = 10.5%
EE = 1.93%
OMD = 86%
is UFL or UFV value higher
UFL milk production more efficient as using energy
for every 50kg in bodyweight change UFL changes approx how much?
0.3 UFL
what is the maintenance requirement of a 600kg cow in UFL’s
5 UFL
approx how many UFL’s are per kg of milk
0.44 UFL
1 kg body weight loss is equal to how many UFL’s
3.5 UFL
1kg body weight gain is equal to how many UFL’s
4.5 UFL
do you add or subtract associative effects
subtract
what causes associative effect
increase concentrates reduce rumen pH, this reduces the effectiveness of the fibre microbes hence reducing forage breakdown
what is the housing adjustment for loose housing cows
10%
what is housing adjustment for pasture based cows
20%
UFL requirement for 7th month gestation cow
0.9 UFL
UFL requirement for 8th month gestation cow
1.6 UFL
UFL requirement for 9th month gestation low
2.6 UFL
