Jefferson County Fair requires all junior market beef, sheep, swine and goats to have official USDA 840 ear tag and official DNA hair sample identification. Click below for more information. 840 RFID ear tags and DNA identification envelopes are available for purchase at the Jefferson County Fair Park Office (8 am to 4 pm weekdays) or online by credit card at jcfairpark.com (online purchased tags and envelopes must be pick up at the Jefferson County Fair Office.)