Number identification in a beef cow enterprise can sometimes be difficult to formulate. Having the birth year as the first digit is a good idea. This will help you quickly determine the age of a female. The next digits in your system relate back to the dam. If you try to maintain this system, the ID of a calf could be 10 to 12 digits long, depending on the number of years the original dam stays in the system. Consider leaving the birth year as the first digit, then making the next digit the birth order. So the first calf born in 2009 could be identified as 9001, the second calf 9002, etc. In your calving book, you would have the dam ID and then the corresponding calf ID to “mother” them up if they get separated. Some producers put the same number in the calf as the dam at calving to easily mother pairs up if they become separated or to “pair” out. Then at weaning, heifers that are retained as replacements get their permanent ID based on year and birth order, as illustrated above. Finally, there is an international numbering system that denotes each year by a letter. The letter for 2009 is V, so the ID of calves could begin or end with the letter V, and after or before the V could be the order of birth during the calving season. For a reference, see this publication from the University of Arkansas Cooperative Extension Service: Beef Cattle Identification. If you are keeping records, an ear tag plus either a tattoo or number brand (freeze or hot brand) would be advisable. Ear tags are not a form of permanent ID, as they can fall out. If you have a number of cows that lose their ear tags and you don’t have a form of permanent ID, then those records may be lost, as you can’t match cows with the data.