Yes, according to the statute you cited, when you "slaughter" your poultry, you may not have any "employees" around. Of course because of the wording, there are ways around that if you wish to play those kind of games
However, California is following Federal Law as allowed by U.S.C. TITLE 21; CHAPTER 10; § 454.
§ 455 & § 456 of the same Title & Chapter discuss inspection. § 458 of the same above discuss Prohibited Acts. § 464 of the same above discusses Exemptions.
Remember Federal Statutes can't be superseded by State Statues, but they can be made stronger, which is what I think you will find in U.S.C. Title 21; Chapter 10; § 464; Subsection C; Paragraph 1; Clauses C & D. Basically, they allow for the packaging of self-slaughtered poultry for resale under certain condition. It looks like the California Statute simply ADDS another condition, which is allowed under § 454 of the above Title & Chapter.
This is all a preliminary/rough draft piece of advice. I highly advise looking all of this up yourself to make fully sure what the law(s) are if you are interested in Federal Aspect of this. Perhaps the rule about not having employees stems from the Federal Food, Drug, and Cosmetic Act
. Only one way to find out