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Virginia Cooperative Extension -
 Knowledge for the CommonWealth

Is calf ID worth the trouble?

Dairy Pipeline: February 1997

by Bennet Cassell
Extension Dairy Scientist, Genetics and Management
Virginia Tech

"ID" refers to records of an animal's sire, dam, and date of birth. All three pieces of information are important to dairy herd management. Those of you who sell (or aspire to sell) dairy animals on the basis of pedigree merit clearly see the value of good identification. What about herds that never use pedigree information when animals are sold? Such herds still need good identification to avoid inbreeding. Inbreeding reduces milk production, increases embryonic and calf or heifer mortality, and depresses fertility and general vigor. Overall effects of inbreeding may be greater in today's larger herds where animals must fit both facilities and routine management conditions. Today's active AI bulls are more closely related than they were several years ago, meaning that mild inbreeding is tougher to avoid than it used to be. You use natural service bulls from a neighbor's herd? They are usually sons of active AI bulls. Inbreeding may be more difficult to avoid in bull bred herds where one sire has many daughters. Good identification programs rely on complete and accurate records of service sires and breeding dates, plus a rigorous program of tagging calves at the same time navels are dipped. "Fresh" information is more accurate than "stale" information. If you don't know the sire on the day a calf was born, is your knowledge likely to improve over time? Adopt a policy of tagging all potential replacement heifers on the day they are born. Double tagging systems with cross reference records are worth the extra trouble. If you are not sure of a calf's sire and/or dam, don't guess. No identification is less harmful than wrong identification. Calf ID is a thankless task on the day it is performed, but there are no good options available if parentage information is lost.

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