Which hormones or feed additives are approved by the FDA for use in poultry production in the United States?

In the context of poultry production in the United States, it's important to understand that the FDA regulates the use of hormones and feed additives very strictly. Historically, various substances were used in livestock production, but as of now, the FDA has not approved any hormones for use in poultry. This decision stemmed from scientific findings concerning the safety and efficacy of these substances in poultry, as well as consumer health concerns.

Since DES (diethylstilbestrol) and zeranol are examples of substances that were either banned or never approved for use in poultry production, and given that a combination of six types of anabolic steroids also lacks FDA approval for poultry, the correct choice reflects the current regulations that prohibit the use of these substances. Thus, "None of the above substances is approved" accurately summarizes the FDA's position regarding hormones and steroids in poultry production.