How much DDGS for poultry?
Even with constraints, distiller’s dried grains with solubles (DDGS) is
an acceptable feed ingredient that can be used to feed poultry.
Feed cost remains the largest portion of poultry production costs. To control feed cost, poultry nutritionists continue to look for alternative feedstuffs. Traditionally, when
there is a reduced supply or increase in the price of one feed
ingredient (as with maize or corn), nutritionists seek alternative sources of energy and nutrients.
Many believe that all the feed problems created by the use of a
substantial amount of the U.S. corn supply for ethanol production
will be solved with the feeding of distiller’s dried grains with solubles
(DDGS). However, DDGS does not directly replace corn in a poultry
diet and has other constraints, such as price, handling/logistics in
feed mill and nutrient variation, which limit its use. Even with these
constraints, DDGS is an acceptable feed ingredient that can be used
successfully in poultry diets to reduce costs.
Increased government pressure for biofuels has led to a significant
increase in biodiesel production resulting in increased cost for fat.
Demethylated glycerin may have some promise as a feed ingredient
for poultry diets. But issues with product consistency – methanol,
sodium or potassium – moisture levels and feed flow, handling and
manufacturing need to be better understood.
DDGS does not directly replace corn
Many believe that all the feed problems created by the use of a
substantial amount of the nation’s corn supply for ethanol production
will be solved with the feeding of DDGS. However, DDGS does not
directly replace corn in a poultry diet (it will replace corn, soybean meal,
meat and bone meal, phosphorus, methionine, etc., and thus its use
will depend on the price of all these) and has other constraints.
Currently, the main issues with DDGS are the price, availability
and logistics/transportation. There is also high variation in its nutrient
content (Table 1) and quality, such as for protein (especially for lysine
digestibility), fat and phosphorus. The energy value of DDGS for poultry
is approximately 17% lower than that for corn ( 1,280 versus 1,540 kcal/
lb, respectively) and has the most influence on the value of DDGS. The
variation in DDGS can be due to corn (variation in corn from regions), the
processing at the ethanol plant (mash times, temperatures, distillation
process, etc), drying temperatures and the amount of solubles that are
added back (Table 2; Noll et al., 2006) to the product.
Between plants, and sometimes even within plants, there can be a
high variation in the moisture level, lysine digestibility, sodium, protein and
phosphorus. Reliable nutrient values are important to obtain when using
DDGS in poultry diets, especially when high levels of inclusion are being
used, as the risk associated with nutrient variability becomes greater.
Phosphorus
DDGS contains a substantial amount of total phosphorus (0.72%;
Martinez-Amezcua et al., 2004). The relative P bioavailability of DDGS
is higher than the values reported in NRC (1994) based on table values
for total and nonphytate content. DDGS is a great source of high-available phosphorus ( Table 3). However, there appears to be variability
in P bioavailability among different DDGS samples.
Phosphorus bioavailability appears to increase with heat processing. Phytase has been shown to increase the bioavailability of P in
DDGS. Martinez-Amezcua et al., 2006 estimated that phytase released from 0.049-0.072% P from DDGS (which indicates that phytase
released is approximately 20-28% of the nonbioavailable P in DDGS.
Nutrient variation is not the only challenge with the use of DDGS.
Others include railcars that may have difficultry unloading, the lack of
bin space, issues with handling and flowability, and possibly of greatest
concern is pellet throughput and quality.
Handling solutions
Handling issues with DDGS may be attributed to the flat, plate-like
structure of the bran which results in an arch-formation when DDGS
is stored. There are a few approaches that can help improve the flow
characteristics of DDGS. However, most need to be implemented at
the ethanol plant.
Just as levels of nutrients are tripled in DDGS as compared with
the original grain, this also applies to concentration of mycotoxins.
Mycotoxins are not destroyed by fermentation. However, while mycotoxins may occur, this is considered to be relatively unlikely by the
alcohol industry. Corn that has been improperly stored and developed
Table 1. Average nutrient composition of DDGS for poultry
Component (%)
TME (kcal/kg)
Lysine
Lysine Dig.
Methionine
Methionine Dig.
Threonine
Threonine Dig.
Fat
CA
P
P Avail.
Na
Mean
2,863
0.78
72
0.49
88
0.98
76
10
0.03
0.73
70
0.25
Range
2607-3054
0.59-0.89
46-84
0.41-0.60
85-92
0.85-1.14
69-83
4-16
0.02-0.04
0.62-0.77
64-100
005-0.45
CV (%)
3. 6
11. 6
11. 2
9. 7
1. 9
6.0
4. 8
4. 8
38.4
5. 3
32.8
The above table shows the nutrient content variability of DDGS, such
as protein, fat and phosphorus.
