Many new parallel parlors are designed to include electronic identification systems. Some even provide individual cow indexing so that the neck rail can fit snuggly and move the cow as far back as possible.

If you are retro-fitting an existing parlor to a parallel parlor without electronic ID, there are a couple of options. Double leg bands from Nasco can be effective. Get the kind with the numbers imprinted into the plastic because the black paint wears off. Blank bands with numbers painted/written on them eventually wear off too. A hose in the parlor can help clean them off if too much manure gets on them.

Brisket tags are a possibility, but placement is important because milkers need to be able to look between the legs to see the brisket tag all the way in front.

Depending on how much of the hind leg is visible in your parlor, freeze brands on the rear leg can be effective too. The problem with freeze brands is legibility of the brand and hair growth after the brand has been on a while.

Dick Wallace, Dairy Extension Veterinarian, University of Illinois - Illini DairyNET

You can use your same ear tags as in any parlor, or the new RFID ear tags give you the option of electronically identifying cows, which may be an advantage if you use DHIA and they provide that option for identification.

Dave Bray, University of Florida Animal Sciences Department