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Virginia Cooperative Extension - Knowledge for the CommonWealth

Suggestions for crossbreeding dairy cows

Dairy Pipeline: October 2001

Bennet Cassell
Extension Dairy Scientist, Genetics and Management
540/231-4762
Email: bcassell@vt.edu

We haven't produced any new crossbreeding research in this country for 30 years, but interest is growing and some dairy farmers are pressing ahead courageously with crossbreeding programs. While we don't know the specifics of how modern genetics will fair in a crossbreeding program, there are some logical steps that the early-adaptors should follow. I have heard of producers using crossbred bulls in natural service. This bothers me because these animals cannot be progeny tested and I have real doubts that their parents were intensively selected. Use of a HxJ crossbred bull on a straightbred Holstein or Jersey cow will produce only 50% of the heterosis that would result from a cross of two purebred lines. More importantly, farmers can practice selection within purebred lines using bull proofs and AI. PTA's rank bulls accurately within breed, and almost certainly identify the best group of bulls to use in crossbreeding programs. It would take a large, expensive, and very carefully planned breeding trial to convince me that the best bulls for a crossbreeding program were NOT on the top of the Net Merit lists we have today. Backcrossing a parent breed on crossbred cows will produce half the heterosis in second-generation offspring that would result from crosses to a third breed like Brown Swiss. A crossbreeding program needs near-maximum heterosis to improve reproduction, disease resistance, and health traits. Crossbreds will take a "hit" on production compared to Holsteins on a per-lactation basis, and we need better performance in the "functionality" traits to make up the difference in lifetime economic merit. Crossbreeding is a business decision that cannot be easily undone. Plan carefully and execute well.



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