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

FINISHING
A beef finishing feedlot diet is unique. Animals are expected to gain at a rate to maximize growth, lay down
adequate marbling, deposit backfat, and maximize carcass yield all within a limited time frame. Usually, cattle are
gradually introduced to an 85% grain-based finishing diet (Gibb et al, 2008). Wheat DDGS can be substituted for
a portion of the concentrate (grain) in the ration depending on opportunity costs.
As seen in Table 5, wheat DDGS can be successfully incorporated to replace a portion of grain within finishing
diets with no identified adverse impact on animal productivity.
When evaluating a potential new feedstuff for feedlot cattle, productivity is typically the first thing that is looked
at. However, product quality and meeting consumer expectations is just as important. In many ways, corn
DDGS research has provided insight into the impact that feeding wheat DDGS will have on ruminants. The effect
that corn DDGS has on meat quality and carcass traits has been debated. In a review of the literature, Walter
(2010) noted that marbling scores steadily decreased with increases in corn DDGS at inclusion rates over 23%.
Concurrently, carcass hot weight and yield grade increased. Meat quality, including shelf life and colour and
stability, has been noted to decrease with higher levels (40-50 %) of corn DDGS feeding (Aldai et al., 2009). In
contrast, Swanson (2010) found that when corn DDGS was included in finishing diets at 0%, 17%, 33%, and
50% there were no significant differences between dressing percentage, marbling score, and yield grade.
With these contradictions and some obvious differences in wheat DDGS nutrient composition, FOBI researchers
led an in-depth study of meat quality and carcass traits to compare wheat DDGS to corn DDGS on performance,
carcass and meat quality characteristics of cattle (Aldai et al., 2009; Walter et al., 2010; Aldai et al., 2010). Walter
et al. (2010) included 40% wheat DDGS or corn DDGS in finishing diets with no identified negative impact on
carcass quality or sub-primal boneless boxed beef yields. Animals fed wheat DDGS included at 20% or 40%
produced backfat, yield, ribeye area and marbling scores consistent with barley-finished cattle (Aldai et al.,
2009). Within the same trial, animals fed corn DDGS had greater backfat, lower lean yield, and less ribeye area in
comparison to animals fed barley and wheat DDGS (Aldai et al., 2009). Aldai et al. (2009) noted that three other
Canadian studies agreed with their findings.
Meat quality from animals fed wheat DDGS is comparable with that currently produced with more traditional diets
in Canadian beef production systems. Aldai et al. (2009) fed animals 20% and 40% wheat DDGS with no change
in meat quality (chemical composition, cooking time, cooking loss, tenderness, drip loss, colour) or differences
in sensory tests (taste, smell, sight). Stoll et al. (2010) found steaks from steers fed wheat DDGS were lighter,
but meat and cooking characteristics were not affected. Although steaks from barley-fed steers held their colour
better, steaks from animals fed wheat DDGS had better colour stability than steaks from animals fed corn DDGS
(Stoll et al., 2010).
When ethanol is produced, starch is removed from the grain and as a result the byproduct has minimal starch
content and other nutrients such as protein, fibre and oil are concentrated. The increased fat content, particularly
with corn DDGS, has the potential to alter fat composition of the beef carcass. The addition of wheat DDGS to
the diet (20-40% DMI) decreased the fatty acid isomers 10t-18:1 (unhealthy trans fat isomer) and increased the
fatty acid isomer 11t:18:1 (health promoting isomer) in studies conducted by Aldai et al. (2010) and Dugan et al.
(2010). These researchers concluded that the change was not great enough to warrant the addition of wheat
DDGS in diets simply to alter trans 18:1 (11t:10t ratio) for the benefit of consumers.
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RUMINANT DIETS