Crossbreeding: Summary of the 2007 Peterson symposium
Published in Dairy Star June 23, 2007
W.E. Petersen, pioneer U of M dairy scientist.
W.E. Petersen was a pioneer dairy scientist at the University of Minnesota. The Danish-American professor conducted landmark research in the physiology of lactation and other aspects of dairy husbandry in the first half of the 20th century. His family and other admirers sponsor a biennial educational program at the University of Minnesota St. Paul Campus on a topic of current interest in his honor. This year the symposium featured an international roster of presenters on the topic of crossbreeding dairy cattle. Crossbreeding is practiced by an increasing number of dairy farmers to improve the fertility and durability of their dairy herds.
Bennet Cassel, Virginia Polytechnic University and Hoard’s Dairyman columnist delved into the biology of crossbreeding. Cattle have thousands of genes that are arranged in pairs, one of the pair received from the female parent and the other from the sire. The more closely the parents are related, the more likely a calf is to receive carbon copies of genes from its parents. The more pairs of genes that are identical, the higher the level of inbreeding that occurs. Inbreeding has been shown to decrease the viability and performance of all kinds of creatures, including dairy cattle. We know that intense selection of dairy animals, implemented by extensive use of closely related bulls via artificial insemination, has led to increased inbreeding. Crossbreeding is the opposite of inbreeding. It is the mating of unrelated animals of different breeds. Cross breeding has the benefit of decreasing inbreeding, allows the introduction of beneficial genes from different breeds, and provides heterosis, also called highbred vigor. Heterosis is the increment by which crossbred animals excellence the average of the parent breeds for a given trait. Effective crossbreeding systems are planned with designated rotations of breeds and can become quite complex. Do you criss-cross two breeds, or implement a three-breed rotation, or use a variety of breeds willy-nilly? A three-breed cross provides flexibility in selecting breeds and provides good opportunity to retain a high level of heterosis.
Dairyman Kevin Prins, Oakdale, CA, switched from pure Holsteins to crossbreeding in 2000 because of frustration with fertility and calf survival. He reported higher quality colostrum, improved calving ease and calf survival, easier transitioning of fresh cows, higher body condition, improved heat detection, higher conception rates, reduced mastitis and somatic cell counts, and stronger feet and legs in his crossbreds. He has not lost production with the crossbreeding. Presently his plan is a three-breed cross – Montbeliarde bred to Holstein with Swedish Red brought in as the third breed. He is experimenting with bringing Danish Red in as a fourth breed. He says crossbreeding has improved his quality of life by reducing cow problems and is experiencing the joy of working with healthy animals.
Morten Kargo Sørensen, Danish Cattle Federation and Aarhus University, Denmark, emphasized the importance of breeding goals and the definition of breeding goals as critical for the development of a sustainable herd. Over the long range, production, economics, and herd health considerations will be key factors in setting sustainable breeding goals. In Denmark, crossbreeding often starts with breeding Holstein cows to one of the Nordic Red breeds. The Nordic Red breeds are Swedish Red, Norwegian Red, Finnish Ayrshire and Danish Red. Jersey is the predominant choice for a third breed because a significant number of Jersey bulls are progeny tested each year, although the introduction of Jersey creates variation in animal size and milk composition. Sørensen concluded that crossbreeding can provide dairy producers with increased economic output and improve the welfare of animals at the herd level, but crossbreeding is not “the total solution” for herds with low management levels or with fertility problems. As herd sizes increase and farmers spend less time with each cow, robust cows will be more important in the future. He also pointed out that crossbreeding doesn’t substitute for adoption of sustainable breeding goals in the pure breeds, which are required as a source of genetics for the crossbreeding program.
Other presentations included University of Minnesota Researcher Brad Heins on the results of cross breeding research in Minnesota and California, USDA scientist Paul VanRaden on genetic evaluation of all breeds with crossbreds included, and a panel of Minnesota dairy farmers – Dana Allen, Eyota; Joe Becker, Eden Valley; and Joe Molitor, St Cloud.
Swedish Red x Holstein crossbreed, 32,000 lb milk M.E. and 30,000 SCC.
More detailed information from presentations at the Petersen Symposium on crossbreeding dairy cattle can be found at http://www.ansci.umn.edu/petersen2007.htm. University of Minnesota crossbred cattle, including three-breed crosses of Holstein x Jersey x Montbeliarde, can be observed at the St. Paul Campus dairy barn or the West Central Research and Outreach Center at Morris. A smaller low input herd comprised of a three-breed cross of Holstein x Jersey x Scandinavian Red, which includes New Zealand genetics, is also located at Morris.