If you read the linked article the FDA is saying that spent grain (and facilities that produce them) will be covered by Subpart C, which it summaries like this:
The Agency proposes to require that the owner, operator, or agent in charge of a facility have and implement a written food safety plan that includes as applicable:
- A hazard analysis;
- Preventive controls;
- Monitoring procedures;
- Corrective Action procedures;
- Verification procedures;
- A recall plan.
If you drill down further, you'll find that many of those bullet points apply only to cases where "hazards that are reasonably likely to occur" exist.
I can't make out what special equipment this would require, and the claim that it would require that "the feed has to be dried, analyzed and packaged" is obvious nonsense. I really wish the curators of BoingBoing would exhibit even the a little bit of skepticism before publishing FUD.
(Text of the rule is here; search for "D. Proposed Subpart C—Hazard Analysis and Risk-Based Preventive Controls" to locate relevant section.)