energetic evaluation of feeds · energetic evaluation of feeds (questions: i/3, i/4, and i/5.) what...
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ENERGETIC EVALUATION OF FEEDS
István HULLÁR (2020.)
associate professor,
(Rottenbiller Str. 50., e-mail: [email protected])
ENERGETIC EVALUATION OF FEEDS(Questions: I/3, I/4, and I/5.)
What are the nutrients required for?
- For the synthesis of body tissues and
animal products;
- as sources of energy (for maintenance and
production).
NUTRIENT and ENERGY content of feeds(for demonstration only)
DM Ash CP EE CF NFE
Feed (g/kg feed) (g/kg DM)
Barley 873 28 128 21 49 774
Alfalfa 228 117 204 29 279 371
etc.;
DE ME NEm NEl NEg
Feed (MJ/kg DM)
Barley 13.4 13.1 8.6 8.0 5.8
Alfalfa 10.5 7.9 6.6 6.5 4.1
etc.
ENERETIC EVALUATION OF FEEDS
Aims:
to express
− the energy requirements of animals and
− the energy contents of their feeds by the
same energy terms.
Exam Question I/3.
Energetic Evaluation of Feeds I.
Conceptions (GE, DE, ME, NEm, NEl,
NEg, q-, k-, and i-values).
The possible energy terms:
Gross Energy (GE),
Digestible Energy (DE);
Metabolizable Energy (ME);
Net Energy for maintenance (NEm);
Net Energy for lactation (NEl);
Net Energy for gain (NEg).
Conceptions
FLOW DIAGRAM OF ENERGY TERMS
GE (Gross Energy or BE: Brutto Energy)
- Faecal Energy loss
DE (Digestible Energy)
- Urinary and Gaseous (rumen and gut) Energy Losses
ME (Metabolizable Energy)
- Heat Increment
NEm NEl NEg (Net Energy)
(m: maintenance; l: lactation; g: gain).
Bomb calorimeter (a strong steel vessel)
Energy units of measure
Joule (J);
1 cal = 4.184 J;
International System of Units (SI) prefixes:
103 = kilo; 106 = mega;
1 000 J (103 J) = 1 kJ (kilo joule);
1 000 000 J (106 J) = 1000 kJ = 1 MJ (mega joule).
Energy units of measure
• Energy Contents of Feeds:
MJ/kg or MJ/kg DM;
kJ/g or kJ/g DM;
1 kJ/g = 1 MJ/kg;
• Energy Requirements of animals
Monogastric animals: MJ/kg of feed;
Ruminants: MJ/day.
The matabolizability („q”), feeding level („i”:
intensity of feeding), and the partial
transformation factor („k”)
GE
- Faecal Energy loss
q = (ME/GE)*100 DE
- Urinary and Gaseous
Energy Intake Energy loss
i = −−−−−−−−−−−−−−−−−−−−−−−− ME
Energy Required for Maintenance - Heat loss
k = (NE/ME)*100 = 70-80% = 60-70% = 30-50%
NEm NEl NEg.
Exam Question I/4.
Energetic Evaluation of Feeds II.
Monogastric animals (energy types,
reasons of their use in the given species).
Principles (a, b, c) and practice (d, e) of a
modern energy evaluation system
a) Energy requirement of animals and energy content of their feeds must be expressed with the same type of energy;
b) it should be additive (substitution of feeds by each other);
c) it should be exact (positive correlation between the feed energy term used and animal production);
d) simplicity (determination or prediction of feed energy by simple methods or parameters;
e) practicability (easy use in the nutrition practice);
ACCURACY vs. SIMPLICITY.
Energetic Evaluation of Feeds II.
Monogastric animals
GE
- Faecal Energy
DE (MJ/kg)
Swine, Horse, Rabbit
Energetic Evaluation of Feeds II.
Monogastric animals
GE
- Faecal Energy loss
DE
- Urinary and Gaseous Energy
Losses
ME (MJ/kg)
Poultry: AMEn
(Apparent Metabolizable
Energy corrected to zero
N retention.)
Other Species: different possibilities
Dogs Cats
Possibilities
DE, ME ME
Other Species: different possibilities
Fur Bred Animals
Possibilities
Herbivorous Carnivorous(Nutria, Chinchilla) (Polecat, Mink, Fox)
DE ME
Exam Question I/5.
Energetic Evaluation of Feeds III.
Ruminants (energy types, reasons of their
use in the given species).
Energetic Evaluation of Feeds III.
Ruminants
GE
- Faecal Energy loss
DE
- Urinary and
Gaseous Energy
Losses
ME
- Heat loss
NEm NEl NEg.
• Dairy Cow:
NEl (MJ/day)
Energetic Evaluation of Feeds III.
Ruminants
GE
- Faecal Energy loss
DE
- Urinary and
Gaseous Energy
Losses
ME
- Heat loss
NEm NEl NEg.
- Beef Cattle,
- Dairy Heifers,
- Sheep.
Change of the partial transformation factor („k”)
according to the matabolizability („q”)
The matabolizability („q”), and the partial
transformation factor („k”)
GE
- Faecal Energy loss
q = (ME/GE)*100 DE
- Urinary and Gaseous
Energy loss
ME
- Heat loss
k = (NE/ME)*100 = 70-80% = 60-70% = 30-50%
NEm NEl NEg.
Other Species: different possibilities
Goat
Dairy Meat Type
Possibilities
NEl NEm+NEg.