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

The calcium (Ca):phosphorus (P) ratio in wheat DDGS is approximately 0.18:1 (see nutrient composition tables
at the end of this guide). Wheat DDGS may contain more than 1% phosphorus compared to 0.3% in barley
grain, while calcium levels are typically 0.15% of DM (McKinnon and Walker, 2008). A 2:1 Ca:P ratio in ruminant
feeds has been the industry standard formulation to prevent metabolic and urinary problems associated with
an imbalance of these two minerals (NRC, 1996). Most ruminant diets, particularly finishing diets, will require
supplemental calcium when DDGS are fed. The implication of excess dietary phosphorous in DDGS-based diets
is further discussed in the ruminant manure management sub-section.
Sub-Acute Rumen Acidosis (SARA) is a condition that can occur in ruminants when rumen pH drops below
5.8 for extended periods of time (Li et al., 2010). The cause is most likely due to diet fibre not being ‘physically
effective 1 ’ coupled with a diet high in starch. SARA lowers feed intake, decreases gains and can result in liver
abscess problems (Walter, 2010; Beliveau and McKinnon, 2009).
Until recently, researchers hypothesized that wheat DDGS may decrease the occurrence of SARA due to its
relatively low-starch and high-fibre content. However, Beliveau and McKinnon (2009) have shown that even
though wheat DDGS is a low-starch, high-fibre product, the small particle size does not allow it to be physically
effective in reducing SARA. As a result wheat DDGS is not effective in stimulating sufficient chewing activity to
generate saliva production that would help buffer rumen pH when DDGS replaces a portion of the barley grain
in an 89% barley grain diet. Beliveau and McKinnon (2009) also suggest that the low pH (4.3) of wheat DDGS
may negatively impact rumen pH. Similar results were noted by Walter et al. (2010) who concluded that replacing
barley grain with up to 40% wheat DDGS did not mitigate rumen fermentation processes associated with
acidosis. Li et al. (2010) reported that feeding a concentrate-based diet, where wheat DDGS replaced mainly
barley silage at 30% (5% silage remaining) and 35% DM (silage excluded), lowered rumen pH below 5.8 for 14
hours. Feeding 25% DDGS (10% silage remaining) resulted in no change in the amount of time (10 hours) rumen
pH was lowered, as compared to the control.
COW/CALF PRODUCTION
The current trend within the cow/calf industry is towards low-cost extensive winter feeding with a focus on
environmental sustainability. Typically lower-quality forages high in fibre and low in protein are the basis for these
operations. Forage-based wintering beef cow diets normally require supplementation to meet late pregnancy
nutritional requirements (Van De Kerckhove and Lardner, 2008).
Van De Kerckhove and Lardner (2008) found that in an extensive chaff/hay grazing system 2 supplemented with
rolled barley, wheat DDGS or 50:50 rolled barley:wheat DDGS fed at levels to meet the cows’ total digestible
nutrients (TDN) needs, that wheat DDGS was an acceptable alternative to barley grain as an energy and protein
supplement. In this work, all supplementation regimes resulted in similar weight increases (-2.27 to + 11.79
kilograms), and positive changes to body condition scores (0.1-0.2 change) and rump (1-3 millimeters) and rib fat
(0.6-1.1 millimeters) increase.
BACKGROUNDING
Backgrounding is the process of growing cattle at moderate rates of gain. The goal is to develop frame
and muscle, yet minimize fat deposition. Typically target gains are 0.9-1.2 kg/day, depending on the type of
cattle being backgrounded. Such gains can be achieved in a feedlot or on-farm through a forage-based diet
supplemented with a protein and energy source (Clark and Lardner, 2009).
1 Physical effectiveness is calculated by multiplying total NDF by particles sized over 1.18 mm (Mertens, 1997).
2 With the addition of equipment and slight modifications to a combine, chaff can be collected during combining and left in the field or hauled
to a centralized location to be utilized as a feedstuff.
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RUMINANT DIETS