According to the USDA National Organic Program (NOP) Standards rules passed on October 22, 2002, certified organic livestock, including beef, must come from a fully verifiable production system that collects information on the history of every animal in the program, including its breed history, veterinary care, and feed.
Natural beef producers may choose not to use antibiotics or growth-promoting hormones, but there is no third-party verification system required by the USDA.
[citation needed] As organic cattle approach market weight, there are two feeding methods that producers most commonly use to deliver beef products to their customers: “grass-fed” and “grain-fed”.
In the “grass-fed” program, the cattle continue to eat certified organic grass right up to the time of slaughter.
The USDA is currently developing guidelines to define the term “grass-fed”, and it is expected to call for an all-grass diet of at least 95%.