In 1996, U.S. distillers grain production was about 1.0 million metric tons. In 2016, it is estimated that U.S. distillers grain production will be more than 40 mmt. This is a 39 mmt increase over a 20-year period. As a comparison, U.S. soybean meal production increased by only 9 mmt over this same period.
With the volume and growth rate of distillers grain production, it comes as little surprise that we are discussing distillers grain nutrition. However, what may be surprising is how much variability there actually is in distillers grains and how this may be affecting livestock diet formulation.
Source of variability
Although the general process for ethanol production is the same in that yeasts ferment starch from feedstocks to produce ethanol, the exact process is complicated and involves many variables. Factors such as facilities, management and overall business objectives are unique for each biorefinery, and as a result, co-product production and quality tend to vary.
Furthermore, since the only components removed from the grain during the fermentation process are the starch and soluble carbohydrate components, variability in the grain source ultimately causes additional variability in distillers grains.
Protein
One concern for livestock nutritionists when feeding distillers grains is the quality of protein and, specifically, the effect the drying process has on protein digestibility. As a result, numerous research projects have been conducted with poultry and swine models to investigate the effect of drying on protein and amino acid quality.
Data from that research can be used to estimate protein variability in the monogastric model; however, those data may not be applicable to the ruminant model. The amount of protein that escapes ruminal degradation, as well as the amount digested in the intestines, is required to correctly determine the value in a ruminant animal.
Continue reading this article published in Feed Strategy.
