Consistency is key: Unlocking the potential of distillers grains
When identifying potential ingredients as a displacement in formulations, things like nutrient composition, digestibility and price are some of the first criteria. However, many people miss another important criterion: consistency.
By improving consistency in feed ingredients, livestock producers improve feed costs and efficiency in their operations. Contrary to popular opinion, distillers dried grains with solubles (DDGS) are among the most consistent ingredients on the market.
Much of the nutrition industry perceives distillers grains as an extremely variable coproduct. This perception probably arose from the early years of rapid growth in the bioethanol industry. Today, bioethanol producers have identified the nutritional value of the coproducts and place much more emphasis on producing a consistent, high-quality ingredient.
Figure 1 – Coefficient of variation for protein in various feed ingredients.
Data from the Global Data Summary of a commercial feed laboratory highlights this relationship. Figure 1 shows the coefficient of variation (CV) (calculated by dividing the standard deviation by the mean) of the protein content in samples taken for several different ingredients over the past year.
The DDGS from the commercial feed laboratory had a CV of 11.44%. This matched up very similarly to other commonly used protein supplements such as whole cottonseed, canola meal and soybean meal. However, when we look at the CV of protein in samples from a single bioethanol producer or bioprocessing facility, we observe even more consistency.
How does this impact formulations on the farm?
Let’s consider a producer who purchases DDGS that contains 32.5% protein (DM basis) and a standard deviation of 3.75. This means that 16% of the loads of DDGS would have protein <28.8%, and 16% of the loads with protein > 36.25%. A range of 7.5 percentage points. If that same producer purchased DDGS that averaged the same protein (32.5%) but had a standard deviation of only 1.5, then they would have a range of 3.0 percentage points.
If the formulation included DDGS at 10% inclusion, then the protein content in the diet could change ±0.4 percentage points for the more variable DDGS and only ±0.15 percentage points for the less variable DDGS.
This delivers certain practical advantages:
- Opportunities to increase inclusion in the formulation. If an ingredient works in a least-cost formulation, it provides the required nutrients at the most economical price. Having the confidence in consistency to increase the maximum inclusion would deliver even more savings.
- Nutritionists often formulate with safety margins to ensure that the formulation provides sufficient nutrients. A more consistent ingredient allows the nutritionist to reduce that safety margin and save costs related to over-formulation.
- Improve sustainability. Over-formulation not only represents an added expense but also a waste. Excess nutrients are excreted by the animal and result in damage to the environment. This matches up with the concept of precision nutrition.
These data points clearly show the advances the bioethanol industry has made in producing a consistent and valuable ingredient. We can never completely eliminate variability with any ingredient. However, compared with other commonly used ingredients, DDGS has similar or even less variability. In order to maintain this type of quality, bioethanol producers continue to perform frequent nutrient analysis. Work with your DDGS supplier to learn more about these efforts.
