Wheat DDGS Feed Guide - Western Canadian Feed Innovation ...

AMINO ACID DIGESTIBILITy
The standardized ileal digestibility (SID) of amino acids was higher in wheat than in wheat DDGS (Widyaratne
and Zijlstra 2008), especially for lysine (71.4% vs 46.4%), indicating that heat damage of lysine during the
manufacturing process likely occurred. Nonetheless, the SID content of amino acids was higher in wheat DDGS
due to the higher content of total amino acids. The reduced (apparent) digestibility of amino acids for wheat
DDGS compared to wheat was also observed by Nyachoti et al. (2005). yan et al. (2008) reported SID values for
lysine, threonine, and methionine of 49%, 72.3% and 78%, respectively. Cozannet et al. (2010) reported a mean
SID of lysine in wheat DDGS to be 55.6%. However, these authors also showed that lysine SID was dependent
on processing conditions, as shown by colour of the final wheat DDGS product. Samples with dark colouration,
indicating the browning (Maillard) reaction occurred during processing, had a mean SID of lysine of 55% while
lighter-coloured samples had a mean SID of lysine of 79%. The mean SID values for threonine and methionine
were 75% and 72%, respectively. These authors also showed that the SID of lysine was highly correlated (-0.84)
to the protein content of the acid detergent fibre (ADF) in wheat DDGS.
The addition of xylanase did not improve the apparent ileal digestibility (AID) of lysine in wheat DDGS (Emiola et
al. 2009) regardless of inclusion level (15% or 30%). However, the AID of lysine in this study was approximately
74%, indicating that less damage had occurred during the drying process. Similarly, yáñez et al. (2011) reported
that the addition of phytase, with or without xylanase, did not improve the SID of amino acids in wheat:corn (1:1)
DDGS. Grinding the wheat:corn DDGS did improve SID for lysine (70.5% versus 64.3%) but not for threonine or
methionine.
DIETARy INCLUSION AND GROWTH
Thacker et al. (2006) replaced wheat and soybean meal with up to 25% (5% increments) wheat DDGS in grower
diets, and up to 15% (3% increments) in finishing pig diets. Weight gain of grower hogs decreased with increased
wheat DDGS inclusion due to decreased feed intake. However, no effect of wheat DDGS inclusion was noted
in finishing hogs. The DDGS came from an old-style ethanol plant so the nutrient availability (e.g. lysine) of the
wheat DDGS in this study may have been limiting due to high drying temperatures used in the manufacturing
process.
In a follow-up study, Thacker (2009) reported that dietary inclusion of 20% and 12% wheat DDGS in grower
(19.7-43.6 kg) and finisher (43.6-114.3 kg) diets, respectively, did not affect on weight gain, feed intake, or feed
conversion.
Wheat DDGS has been studied in nursery pig diets. Increasing wheat DDGS inclusion from 0-20% at the
expense of soybean meal and wheat was studied in diets balanced for net energy and SID content (Avelar et al.,
2010). Increasing wheat DDGS in the nursery diet reduced feed intake, weight gain and feed efficiency. Up to
10% inclusion growth performance was maintained, whereas inclusion of 15% and 20% wheat DDGS in the diet
decreased body weight of weaned pigs by 0.4 and 5.4 kg, respectively. Therefore wheat DDGS should be limited
to 10% inclusion in nursery diets.
In a commercial-size study by FOBI researchers, wheat DDGS was included in the diets for growing pigs at 0%,
7%, 15%, 22.5% and 30% (Beltranena and Zijlstra, 2010). For every 7.5% increase in wheat DDGS inclusion,
feed efficiency decreased because pigs consumed 42 g/day more feed per kg of body weight gain. As a result,
the monetary return decreased linearly with increasing wheat DDGS inclusion. These authors recommended a
maximum of 20% inclusion of wheat DDGS in diets for growing hogs.
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SWINE DIETS