Nutrient Dynamics summary lectures
Lecture Gerrits Nutrient Partitioning - 17.03 (week 2)
Animal nutrition = matching nutrient requirements
Feeding values, requirements and linear programming
The feeding value is always the potential of a feed ingredient. You have a conflict between the
feeding value and the animal requirements.
You try to match the feeding value with the requirements.
Feeding value of a feed ingredient
,Energy value of a feed ingredient
a. GE – Gross energy
b. DE – Digestible energy
(DE 90% better then GE)
c. ME – Metabolizable energy
(here we take into account the fecal, urinary and gasses losses)
d. NE – Net energy
(here is corrected for heat losses)
It is true that it is 100% ingredient specific. And the more you go down to NE, the more the
animal comes into play. So Yes it depends on the species, age, a lot of things.
But we talk about feed ingredient evaluation → so if we have high CHO ingredient and a high fat
ingredient, there could be a difference in heat losses. For fiber it is also different. And that is one
of the reasons why NE better than ME!
So most countries use NE. (the lower, the more expensive)
In NL, we evaluate our ingredients based on the DE value, and then we take some assumptions
to translate that to NE. and then we can still work with the NE, even tho we do not do all the
indirect calorimetry with all the ingredients. (that is just done once or twice and then you use
those old data to estimate the heat loss for all the different types of nutrients).
→ for pigs and chickens, NE is mostly used.
So, we measure DE for all ingredients, and estimate the heat loss to move to NE.
Protein value of a feed ingredient
a. Crude protein
b. Digestible crude protein
c. Apparent faecal digestible AA
d. Apparent ileal digestible AA
e. True ileal digestible AA (this is the best but most expensive one)
f. standardized ileal digestible AA (corrected for basal endogenous AA)
from CP to DCP, you account for digestive losses. Then you can go to apparent faecal digestible
AA, but in pigs, delivery of AA stops at the SI. So ileal digestibility is better. If we want to account
for the losses by the animal, we go to the true ileal digestibility. But if you want to do that for all
ingredients, you need a lot of money. So therefore, the standardized ileal digestible AA is used
in poultry/pigs. Here endogenous losses are estimated.
Animal requirements
In what unit would you express the requirements of an animal, e.g. for phosphorus (P)?
a. g of P/d; depending on phase of production
- you don’t know how much the animal eat a day, so this is the worst.
, b. g of P/kg of feed
- you need to translate the requirements into something that you put in the feed, so
not per day but per kg of feed
c. g of P/kJ of energy
- if you have a diet with a different energy density, you can correct for this.
- if you have a high dense of feed, you can put a little more phosphorous in the feed, so
relative to energy you can keep it constant this way.
→ so this would be the best one
If animals grow faster, they need more phosphorous.
Feeding values, requirements and linear programming
A different view on requirements…
You could make a diet and take the growth of the pig only into account. But there are a lot of
biological processes.
Nutrient partitioning
If you feed more of a nutrient, then you study what the animal does with those nutrients, you can
learn from it. → translate them into concepts of requirements. You use this to design optimal
animal nutrition.
, • protein-energy interactions: classical titration approach
works for pigs & chickens (not for all species)
You see protein gain of pigs on the y axis. They were fed two different energy intake levels. Black
dots 3 times maintenance requirements and white dots 2,5 times maintenance requirements.
→ Animals are fed a very low amount of protein at the start. When you increase the protein
intake, they will respond by increasing the rate of protein deposition. Up to a point where energy
becomes limiting, if energy becomes limiting, it reaches a plateau. And they will not gain more
protein anymore.
→ but when you feed more energy, 3,0 instead of 2,5: you do see response. But you only see that
response at a high protein intake. If protein is limiting, you do not see response
(op het begin zijn de witte en zwarte bolletjes gewoon samen)
• Corresponding lipid deposition
Again, we have ileal digestible protein intake on the x-axis. But now, on the Y-axis lipid deposition
(g/day) instead of protein deposition.
1. We feed a small amount of protein. If you increase protein intake with the same amount
of energy → the lipid deposition will decrease. (because the animal needs energy for
protein deposition). It decreases until the animal cannot deposit more protein and then
it will be stable.
2. If we feed more energy → Then lipid deposition will be higher than the previous sentence.
And if we increase protein intake again, the lipid deposition will go down as well.
Lecture Gerrits Nutrient Partitioning - 17.03 (week 2)
Animal nutrition = matching nutrient requirements
Feeding values, requirements and linear programming
The feeding value is always the potential of a feed ingredient. You have a conflict between the
feeding value and the animal requirements.
You try to match the feeding value with the requirements.
Feeding value of a feed ingredient
,Energy value of a feed ingredient
a. GE – Gross energy
b. DE – Digestible energy
(DE 90% better then GE)
c. ME – Metabolizable energy
(here we take into account the fecal, urinary and gasses losses)
d. NE – Net energy
(here is corrected for heat losses)
It is true that it is 100% ingredient specific. And the more you go down to NE, the more the
animal comes into play. So Yes it depends on the species, age, a lot of things.
But we talk about feed ingredient evaluation → so if we have high CHO ingredient and a high fat
ingredient, there could be a difference in heat losses. For fiber it is also different. And that is one
of the reasons why NE better than ME!
So most countries use NE. (the lower, the more expensive)
In NL, we evaluate our ingredients based on the DE value, and then we take some assumptions
to translate that to NE. and then we can still work with the NE, even tho we do not do all the
indirect calorimetry with all the ingredients. (that is just done once or twice and then you use
those old data to estimate the heat loss for all the different types of nutrients).
→ for pigs and chickens, NE is mostly used.
So, we measure DE for all ingredients, and estimate the heat loss to move to NE.
Protein value of a feed ingredient
a. Crude protein
b. Digestible crude protein
c. Apparent faecal digestible AA
d. Apparent ileal digestible AA
e. True ileal digestible AA (this is the best but most expensive one)
f. standardized ileal digestible AA (corrected for basal endogenous AA)
from CP to DCP, you account for digestive losses. Then you can go to apparent faecal digestible
AA, but in pigs, delivery of AA stops at the SI. So ileal digestibility is better. If we want to account
for the losses by the animal, we go to the true ileal digestibility. But if you want to do that for all
ingredients, you need a lot of money. So therefore, the standardized ileal digestible AA is used
in poultry/pigs. Here endogenous losses are estimated.
Animal requirements
In what unit would you express the requirements of an animal, e.g. for phosphorus (P)?
a. g of P/d; depending on phase of production
- you don’t know how much the animal eat a day, so this is the worst.
, b. g of P/kg of feed
- you need to translate the requirements into something that you put in the feed, so
not per day but per kg of feed
c. g of P/kJ of energy
- if you have a diet with a different energy density, you can correct for this.
- if you have a high dense of feed, you can put a little more phosphorous in the feed, so
relative to energy you can keep it constant this way.
→ so this would be the best one
If animals grow faster, they need more phosphorous.
Feeding values, requirements and linear programming
A different view on requirements…
You could make a diet and take the growth of the pig only into account. But there are a lot of
biological processes.
Nutrient partitioning
If you feed more of a nutrient, then you study what the animal does with those nutrients, you can
learn from it. → translate them into concepts of requirements. You use this to design optimal
animal nutrition.
, • protein-energy interactions: classical titration approach
works for pigs & chickens (not for all species)
You see protein gain of pigs on the y axis. They were fed two different energy intake levels. Black
dots 3 times maintenance requirements and white dots 2,5 times maintenance requirements.
→ Animals are fed a very low amount of protein at the start. When you increase the protein
intake, they will respond by increasing the rate of protein deposition. Up to a point where energy
becomes limiting, if energy becomes limiting, it reaches a plateau. And they will not gain more
protein anymore.
→ but when you feed more energy, 3,0 instead of 2,5: you do see response. But you only see that
response at a high protein intake. If protein is limiting, you do not see response
(op het begin zijn de witte en zwarte bolletjes gewoon samen)
• Corresponding lipid deposition
Again, we have ileal digestible protein intake on the x-axis. But now, on the Y-axis lipid deposition
(g/day) instead of protein deposition.
1. We feed a small amount of protein. If you increase protein intake with the same amount
of energy → the lipid deposition will decrease. (because the animal needs energy for
protein deposition). It decreases until the animal cannot deposit more protein and then
it will be stable.
2. If we feed more energy → Then lipid deposition will be higher than the previous sentence.
And if we increase protein intake again, the lipid deposition will go down as well.
