For poultry, hogs, and most other livestock, it means that there are no antibiotics in their feed.
For cattle, it means that they have not been injected with antibiotics.
Antibiotic Use Labeling: Variations of ‘Raised without antibiotics’; ‘No antibiotics ever’; ‘No antibiotics administered; No antibiotics’; No antibiotics added. While these terms on labels may mean what they say, without a uniform standard or definition, consumers can’t bne sure what they mean. Practices can vary widely form producer to producer. When in doubt, call the company or research the company website.