Evaluations of crossbred animals
Holstein World: How will the incorporation of crossbred evaluations by the USDA influence the data capturing of crossbred cows with European heritage on DHIA test across the country? Will these bulls get accurate proofs without a US purebred base to compare against?
Dr. Les Hansen: The movement of USDA-AIPL to an across-breed evaluation is a normal progression and is an effort to be applauded. However, continuous refinements in the prediction system will be needed to properly adjust for heterosis (hybrid vigor) that is specific to breed combinations. European breeds with only semen used in the U.S. (and without a purebred cow population in the U.S.) will be at a disadvantage in this regard. Recent research from New Zealand suggests that heterosis from some breed crosses might be much greater for production than has been assumed. The across-breed evaluations should not decrease the accuracy of proofs for Holsteins and other traditional U.S. breeds.
Holstein World: Where can interested dairy producers find more information about implementing crossbreeding into their herd?
Dr. Les Hansen: We have an extensive review paper with results to date from crossbreeding of Holsteins with Scandinavian Red (Swedish Red and Norwegian Red) and Montbeliarde available on-line at:
http://www.ansci.umn.edu/research/californiaupdate2006-lb.pdf
Also, the University of Minnesota is hosting the 4th Biennial W. E. Petersen Symposium on Monday, April 2. The topic is “Crossbreeding of Dairy Cattle: The Science and the Impact”. The list of speakers is impressive. For those who cannot attend, proceedings papers will be posted on the website of the Department of Animal Science, University of Minnesota, shortly after the symposium. To view the brochure reviewing the symposium program:
http://www.ansci.umn.edu/petersen_symposium/2007/PetersenSymposiumBrochure-07.pdf