The corn that was used in ethanol production, now called distillers grains, is then used as livestock feed for cattle, cows, pigs, poultry, fish, etc.
25% of a massive number is still a massive number.
> Because of provisions in the Federal Agriculture Improvement and Reform Act of 1996 that permits farmers to make their own crop planting decisions based on the most profitable crop for a given year, corn acreage in the United States has increased from a Government-mandated low of 60.2 million planted acres in 1983 to close to or exceeding 90 million since 2018. Much of this growth in area and production is a result of expanding ethanol production, which now accounts for nearly 45 percent of total corn use.
https://www.ers.usda.gov/topics/crops/corn-and-other-feed-gr...
It does look like its dropped a bit since that time though.
Still, one wonders if we'd bother with so much of our fields going to grow corn if the main use was just DDGS. I wonder how the economics of everything else in the corn industry would change if we stopped requiring E10.