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Virginia Cooperative Extension - Knowledge for the CommonWealth

Progeny Tested AI Bulls are an Asset

Dairy Pipeline: April 2007

Bennet Cassell
Extension Dairy Scientist, Genetics & Management
(540) 231-4762;


Virginia dairy producers, through AI, have easy and affordable access to the best genetics available anywhere in the world. Ready access brings an abundance of options, sales promotions, do-it-this-way, no, do-it-that-way advice that can minimize apparent value in the minds of producers. But consider the alternative of trying to find decent herd bulls, control diseases, avoid big inbreeding problems, and keep cows and heifers pregnant at the same time. Progeny tested AI bulls are readily available, known commodities with more pedigree variety than can be found in herd bulls. Producers benefit from twiceselected AI bulls. Only the very best, most current pedigrees ever enter the AI sampling programs. There is no way individual farmers can consistently match the pedigree merit of young sires in the PT programs of major studs. A few farmers might find flush-mate to AI young sires for use as a herd bull every once in a while, but there is no way to do that con-sistently. The proven bulls are the very best of
these top pedigreed youngsters – one in ten or less meet proven bull requirements. Herd bulls NEVER face that secondary selection – they’re too old, ornery, and dangerous by that stage of their lives and what are the choices in a single herd anyway? We know SO much more about proven AI bulls – production and conformation, fertility of the bull and his daughters, survival, somatic cell score and the ever important calving difficulty and stillbirth data are all known to one degree or another through progeny tests. Knowledge isn’t perfect on any of these traits, but don’t kid yourself. We know a great deal more from progeny performance than pedigree information can ever reveal. Progeny tested AI bulls are a major resource for US dairy producers. Use them – all the time if you can.

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