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Potential for use of dried distillers grains with solubles (ddgs) in Layer diets

AbstractDistillers Grains are a cereal byproduct of

distillation for bio-energy, ethanol pro-

duction and of growing interest for the

feed industry. DDGS is a raw material rich

in crude protein and amino acids as well

as some minerals, e.g. phosphorus. In this

review, the nutrient content of DDGS is

compared with corn and wheat. DDGS

from wheat has a higher content of crude

protein and amino acids than corn based

DDGS. If DDGS is to be used in diet formu-

lation for laying hens, the first question is

which grain was used for the production

of DDGS. Matrix values are subject to con-

siderable variation between DDGS sour-

ces, due to different plant material and

ethanol production plants. To assure ba-

lanced nutrient content in the compound

feed, it is not advisable to use the maximal

possible level of a cheap, but variable raw

material, and producers of DDGS are trying

to achieve more predictable quality, with

less variation from a single production fa-

cility. If DDGS is used to partially replace

“soya 48 brasil” (46% CP), exchange factors

of 2.2 for corn DDGS (26% CP) and 1.6 for

wheat DDGS (33.5 CP) may be assumed.

All ingredients of the cereals (without

starch) will be increased by a factor of ap-

proximately 3. Quality standards should be

verified before prices are taken into consi-

deration. The plants selling DDGS should

meet the required quality specifications,

with nutrient specifications and proximate

amino acids analysis, mycotoxin analysis

and physical samples of the products. Sci-

entific trials and practical experience have

shown that DDGS from corn, wheat and

other cereals can be a valuable and cost

effective raw material in feed formulation

for poultry and especially for layers. In view

of limitations in the international raw ma-

terial market, DDGS offers an opportunity

to minimize the cost price of nutritionally

optimal diets for laying hens.

IntroductionDDGS is a catchword often heard in the

context of the worldwide raw material

market for poultry feed. DDGS is a co-pro-

duct of the bio-energy or ethanol industry

when producing energy from sustainable

sources. Those are mostly corn and wheat,

but some other plant sources may also be

used to produce bio-ethanol or energy in

general. This article will mainly refer to the

DDGS based on corn and wheat.

What is the meaning of DDGS?Distillers Grains are a cereal byproduct of

the distillation process. There are two main

sources of these grains. The traditional

sources were from brewers. More recently,

ethanol plants are a growing source. It is

created in distilleries by drying mash, and

is subsequently sold for a variety of purpo-

ses, usually as raw material for livestock – in

the past mainly or especially for ruminants.

Potential for Use of Dried Distillers Grains with Solubles (DDGS) in Layer Diets

Robert Pottgüterrobert Pottgüter studied Agricultural science at the university of Bonn, spe-cialized in animal nutrition and worked in leading positions in the feed indus-try before joining Lohmann tierzucht as chief nutritionist. in this article he takes a critical look at ddgs, a raw material which may be used to reduce feed cost – with due attention to the variable quality.

to contact the author: Mail at pottgueter@ltz.de

Vol. 49 (1), July 2015 | LOHMANN Information

19

There are two common types of distillers

grains:

Wet Distillers Grains

Wet Distillers Grains (WDG) contain prima-

rily unfermented grain residues (protein, fi-

ber, fat and up to 70% moisture). WDG has

a shelf life of four to five days. Due to the

water content, WDG transport is usually

economically viable within a short distance

from the ethanol production facility only.

Dried Distillers Grains

Dried Distillers Grains with Solubles (DDGS)

is WDG – with the addition of some liquid

co-products from fermentation, dried to

10-12 percent moisture. DDGS have an al-

most indefinite shelf life and may be ship-

ped to any market regardless of its proximi-

ty to an ethanol plant. Drying is costly, as

it requires further energy input. In the USA,

DDGS is packaged and traded as a commo-

dity product and sold on the world raw ma-

terial market. With increasing production of

ethanol from cereals in different parts of

the world, we also find more DDGS being

offered as raw material for livestock. From

each metric ton (MT) of corn or wheat used

for ethanol production we get about of 300

kg of DDGS (with 10% moisture).

Market development for DDGSSince the development of the bio-energy

and ethanol production, there has been

a growing interest of the livestock indus-

try to use the co-products for nutritional

purposes. For decades, wet distillers grains

(WDG) had been used as feedstuff for

different livestock. Major interest started

more recently since Dried Distillers Grains

with Solubles (DDGS) became available in

large quantity due to political programs

with subsidies to encourage production

of energy from sustainable sources. As a

result, DDGS has become an interesting

and cost effective raw material for live-

stock nutrition. The major share of DDGS

will still be used in ruminant nutrition, but

there is also ongoing scientific research

and practical experience in using DDGS in

poultry nutrition (fig. 1).

Nutritional value of DDGSDDGS basically can be described as raw

material quite rich or dense in crude pro-

tein (CP) and amino acids (AA) together

with some minerals, this mainly in regard

to phosphorus. During the production of

ethanol from wheat or corn mainly the

content of starch will be fermented into

ethanol and the residual nutrients will be

concentrated in the “left-over” of the pro-

cess. The nutrient content of DDGS will be

related to the nutrient content of corn and

wheat; i.e. DDGS from wheat will show a

higher content of crude protein and ami-

no acids compared to corn; the different

content of crude protein in the two cereals

will influence CP and amino acid content

in DDGS as well (tab. 2 and 3).

If nutritionists want to use DDGS in diet

formulation, the first question should be

which grain was used for the production

of DDGS, to get an idea of the nutritional

value. But reliable matrix values are dif-

ficult to establish in view of the variation

between DDGS sources – due to different

plant material and even between ethanol

production plants (tab. 1 and 4). This is still

the most serious limitation for using higher

inclusion rates for DDGS in poultry diets.

For efficient growth or egg production,

poultry in general needs a well-balanced

diet with low variation in nutrient content

Fig. 1: usage of DDGS in feed for different speciesSource: Ag MRC agricultural marketing resource center, 2014 courtesy of Dr. Robert Wisner rwwisner@iastate.edu

Table 1: Averages and ranges in compositi-on of selected nutrients in different sources of corn DDGSSource: u.S. Grains council // www.ddgs.umn.edu

Nutrient Average Range

crude protein, % 30,9 28.7–32.9

crude fat, % 10,7 8.8–12.4

crude fiber, % 7,2 5.4–10.4

Ash, % 6 3.0–9.8

calculated Me, kcal/kg

3810 3504–4048

Lysine, % 0,9 0.61–1.06

Arginine, % 1,31 1.01–1.48

tryptophan, % 0,24 0.18–0.28

Methionine, % 0,65 0.54–0.76

Phosphorus, % 0,75 0.42–0.99

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in the compound feed to meet the nutri-

ent demand of each single bird every day.

Because of this, nutritionists prefer to avoid

raw materials known to be variable or keep

the inclusion levels in the formula low. To

be on the safe side, each load of DDGS

should be analyzed before higher levels of

DDGS are included in poultry diets.

All the data above very clearly illustrate

the major nutritional challenge with DDGS

– which is the very big variation of the nu-

trient content – shown under the topic

‘range’ (tab. 5). With the overall target to

achieve a constant nutrient content of the

compound feed, nutritionists will not use

the maximal possible level of variable raw

materials in diet formulation. Producers of

DDGS are aware of this problem and try to

achieve more constant quality with less

variation from a single production facility.

Furthermore there is an ongoing process

to develop different specified co-products

from the ethanol production, e.g. “high

protein DDGS”. Nevertheless we are faced

with the fact that DDGS is considered to

be an interesting commodity in the inter-

Potential for use of dried distillers grains with solubles (ddgs) in Layer diets

Table 2: Digestible amino acid coefficients (%) of DDGS for poultrySource: u.S. Grains council, cited from Wald-roup et al. 2007

Table 3: Composition of wheat compared with wheat and maize DDGS in % of DMSource: Biofuel Co-Products as livestock Feed, FAo 2012

Table 4: Mineral composition and phosphorus digestibility of wheat compared to wheat DDGS and maize DDGS | Source: Biofuel Co-Products as livestock Feed, FAo 2012

Table 5: Varying nutrient content of different DDGS sources, 88% dry matterSource: Evonik AminoDat 4.0

Wheat Wheat DDGS Maize DDGS

dry matter (dM) 86,8 92,7 88,9

Ash 1,8 5 5,8

crude protein 12,1 36,6 30

crude fat 1,7 4,4 10,7

crude fibre 2,5 7,6 8,6

neutral detergent fiber (ndf) 14,3 30,1 41,5

Acid detergent fiber (Adf) 3,6 10,7 16,1

Acid detergent lignin (AdL) 1,2 3,2 –

starch 69,7 5,1 8,2

sugars 2,8 4 –

gross energy (MJ/kg) 16,2 18,67 20,21

Mineral content as % of DM

Wheat Wheat DDGS Maize DDGS

sodium 0,01 0,36 0,22

sulphur 0,17 0,65 0,84

Potassium 0,46 1,07 0,96

calcium 0,08 0,22 0,08

Magnesium 0,12 0,29 -

Zink 0,31 - -

copper 0,06 - -

total Phosphorus 0,37 0,86 0,7

Phytic Phosphorus 0,24 0,23 -

Phytic P/total P (%) 65 27 -

Poultry P availability (%) 58 - 62

Nutrients % DDGS corn - uS DDGS - High protein

DDGS - wheat DDGS - barley

Crude protein

mean 26,1 41,2 31,9 22,6

range  20.2 – 32.4 34.4 – 51.0 23.4 – 40.6 21.1 – 23.8

Lysine 0,76 1,01 0,67 0,72

Methionine  0,5 0,93 0,48 0,36

Met + cys  0,98 1,73 1,08 0,78

threonine 0,98 1,5 0,97 0,8

tryptophan 0,21 0,26 0,33 0,25

Arginine  1,14 1,5 1,31 1,07

isoleucin 0,95 1,59 1,12 0,81

Nutrient Weighted Average

Arginine 85,3

histidine 84,5

isoleucine 82,2

Leucine 89,3

Lysine 68,5

Methionine 86,8

cystine 77,3

Phenylalanine 87,7

threonine 75,1

tryptophan 84,1

Valine 81,4

serine 82,8

Vol. 49 (1), July 2015 | LOHMANN Information

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national raw material market, which needs

special attention concerning specified and

reliable quality and nutrient content.

DDGS offers a chance to re-duce dependence on soyaDDGS is considered as a ‘middle protein

carrier’, with typical content of crude pro-

tein (CP) between soybean meal (higher)

and corn (lower). DDGS can contribute

some of the crude protein (and amino

acids) requirements and reduce the level

of soybean meal and even full fat soya in

diet formulation. As all soybean products

are a ‘wanted’ raw material with high pri-

ce volatility around the world, the inclusi-

on of moderate levels of DDGS in poultry

diets may offer chances for cost saving. In

comparison to “soya 48 brasil” with 46% CP

one can assume exchange factors of 2.2

for corn DDGS (26% CP) and 1.6 for wheat

DDGS (33.5 CP). This means that each 1%

soybean meal can be replaced by 2.2%

corn DDGS and by 1.6% wheat DDGS. This

exchange factor may vary to some extent

according matrix evaluation in detail. The

amount of cost saving will depend on the

actual price setting when offering DDGS

into the diet optimization, especially in re-

lation to prices of soybean products.

Color of DDGSThe color of DDGS gives a first indication

of the quality, lighter and more yellowish

color indicating a higher quality with high-

er amino acid digestibility than DDGS with

darker and brownish color. This is due to

the fact that AA can undergo the Maillard

reaction and AA (especially Lysine) can

be combined with carbohydrates rende-

ring them un-digestible for the animals. It

is thought that the dark color may result

from drying of the wet DDGS in the plants

at too high temperature. The variation

which may be found among samples is

shown in Fig. 1.

Recently scientists have established ad-

ditional quality indicators for an easy and

quick quality test. Color is only a first indi-

cator and should be combined with stan-

dard laboratory tests (tab. 6).

Contamination and unwan-ted residuesIn DDGS everything from the basic cereal

which has not been converted to ethanol

and some minor co-products (for instance

corn oil) during the fermentation process,

will be concentrated. All ingredients of the

cereals (without starch) will be increased

by a factor of approximately 3. First of all,

mycotoxins should be mentioned. DDGS

from cereals with a high load of mycoto-

xins need regular monitoring of mycotoxin

level in DDGS to avoid high contaminati-

on. To control and guide the fermentation

process, some supplements with anti-

biotic activity have been used in ethanol

plants and might be used in the future as

well, specifically Virginiamycin, Penicillin,

Erythromycin, Tylosin and Tetracycline. Salt

(sodium-chloride) used as “drying agent”

to speed up water absorption when dry-

ing the DDGS, will cause undesirable high-

er content of sodium in DDGS.

Checklist when purchasing DDGSSpecial attention needs to be paid to the

quality of the DDGS to be used in poultry

feeds as there is a large variation in quali-

ty between DDGS sources. Receiving low

quality DDGS into a feed mill and including

it in poultry diets can have negative econo-

Fig. 1: Variation of DDGS color in different samples Photo: courtesy of Dr. Jerry Shurson, Department of Animal Science, university of Minnesota.

Table 6: Digestive utilization of nutrients in wheat DDGS and the impact of colorSource: wheat DDGS feed guide – Canada (cited from Cozannet et al. 2009, 2010)

Wheat DDGS

Wheat DDGS

dark Light

Luminance (L) 46,2 57,4

ndf (%dM) 33,6 30,1

Adf (%dM) 18,4 10,7

AdciP (%dM) 41,2 11,6

Lysine (%cP) 1,01 2,29

digestibility

Protein 59,8 81,8

non-essential Amino Acids

64,1 83,9

essential Amino Acids

51 78

Lysine 11,8 60,7

AMe kcal/kg

rooster 2235 2564

Layer 2257 2519

Broiler 2164 2531

turkey 2058 2424

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mic consequences on bird performance.

Poultry feed manufacturers must ensure

they are procuring consistently high qua-

lity corn DDGS to capture the cost savings

for their customers when using them. The

following recommendations should be

considered by poultry feed manufacturers

for the procurement of DDGS

Know the source plant

The quality of DDGS can vary between and

within manufacturing plants due to diffe-

rences in manufacturing processes, process

control, drying technology and ingredient

quality control in the production of DDGS.

Quality standards need to be established

and verified before price is a consideration.

Use an approved supplier process to select

the plants which can provide DDGS that

meet the required quality specifications. This

includes nutrient specifications with proxi-

mate amino acids analysis, mycotoxin ana-

lysis, and physical samples of the products.

Specify the source plant and DDGS

quality in the purchase contracts

Incorporate the DDGS quality specifica-

tions including the analytical methods for

nutrients and the name and location of the

approved source plant into the purchase

contract. Ensure that the supplier can tra-

ce the delivered DDGS back to the origin

plant. This is especially important when

the supplier is bringing multiple sources

of DDGS into the commodity market as

there is a risk that DDGS from different ori-

gins can be mixed up. Verify the supplier’s

product liability insurance coverage.

Inspect the load and retain a sample

Obtain a representative sample of the

DDGS before unloading and verify that it

matches the original sample. Inspect the

color (a dark/brown color may indicate

overheating and lower digestible lysine),

check the odor (a burnt smell also may in-

dicate overheating) and observe the bulk

density and particle size. Reject the load if

the representative sample does not close-

ly match the original.

Monitor DDGS for mycotoxins and nut-

rient content

Mycotoxin content in DDGS is threefold

the level that may be present in the corn or

wheat used for the production of ethanol.

Mycotoxins are NOT harmed or even eradi-

cated by the fermentation process of cereals

into ethanol. Test the DDGS periodically for

mycotoxin content to confirm that exces-

sive levels are not present. Require routine

nutrient information from DDGS suppliers.

Inclusion of DDGS in layer dietsBased on a constant nutrient content with

normal and good digestibility DDGS from

corn, wheat and other cereals will be a va-

luable raw material and cost effective as

well – under nowadays’ high price and vo-

latile raw material markets. Scientific trials

with layer breeds have proven that corn

DGGS could be used with up to 30% in

layer feed formulation. The level of inclusi-

on being possible in practical layer diets is

closely related to the amino acid digestibi-

lity and phosphorus availability; especially

this aspect needs consideration because

available phosphorus has become a quite

costly nutrient constraint in diet formulati-

on for poultry – especially in all vegetable

diets (tab. 7). The proper DDGS nutrient

matrices will, to a very large extent, deter-

mine maximum inclusion rates. It should

be mentioned that Phytase and NSP-Enzy-

mes are high value feed additives in associ-

ation with the use of all kinds and sources

of DDGS in diets for layers and for poultry

in general. Feed structure should never be

compromised, otherwise daily feed intake

might be reduced and DDGS blamed for it.

DDGS from different production plants may

show varying technical quality, i.e. in terms of

flow-ability and specific weight, in addition

to the variation in nutrient content. If buyers

of DDGS are aware of these risks, they should

be able to limit negative consequences.

SummaryDDGS has been well known for a long time

in many countries around the world. With

increasing production of bio-energy and

ethanol from different cereals DDGS has

become an important raw material com-

modity in the international feed market,

especially when based on corn. Scientific

trials and practical experience have shown

that DDGS is a valuable raw material in

feed formulation for poultry and especially

for layers. Due to restrictions and/or high

volatility in the international raw material

market, DDGS may be considered as a new

raw material source for layer feed formu-

lation in additional countries, widening

the basis for diet formulation and offering

more flexibility to lower the cost price of

nutritionally optimal diets.

Potential for use of dried distillers grains with solubles (ddgs) in Layer diets

Table 7: Recommended inclusion levels in practical diets for layers

layer feed type %

Corn DDGS %

Wheat DDGS

starter 5 5

grower 10 7

developer 15 10

Pre-lay feed 15 10

Layer rations 20 15

Recommended check list when buying corn DDGS.

Item Minimum Maximum

crude protein, % 27 -

crude fat, % 9 -

Phosphorus, % 0,55 -

Lysine 2.80% of cP -

Adf, % - 12

ndf, % - 40

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