Department of Animal Science
Date of this Version
December 2005
Abstract
Most ranchers know crossbreeding can increase output, but perhaps, don’t appreciate the potential 25% crossbred advantage in lifetime productivity of crossbred cows. Yes, you read that correctly; 25% crossbred advantage in lifetime productivity. In recent years many commercial cow herds have changed dramatically as producers have opted to repeatedly top-cross Angus bulls on their commercial cows resulting in loss of heterosis and loss of complementary breed effects. Some of the reasons for this shift are; 1) a desire to simplify breeding programs (perception that crossbreeding systems are too complex), 2) use of black hide color as a proxy for market quality, 3) the belief that high percentage purebred commercial cattle produce more uniformity and consistency, 4) effective marketing of the Angus EPD’s and carcass database, and 5) the Angus brand (CAB) impact (desire to get away from marketing commodity products).
A number of textbook crossbreeding systems are not “rancher friendly” in terms of management ease even though they deliver maximum heterosis. Additionally, dealing with grazing rotations, labor constraints and variable market targets require tough decisions that may tilt the crossbreeding system away from the original plan. Utilization of heterosis and breed differences in a crossbreeding system must be coupled with common sense ranch management in such a way that optimum (not maximum) heterosis is produced. There are some simplified crossbreeding systems that can meet this need very well.
Ranchers would be wise to crossbreed even if heterosis was zero, due to the complementary effects of matching strengths of one breed to offset weaknesses of another breed. The opportunity to mate bulls and cows of different breeds or paternal / maternal lines to take advantage of complementarity is an important part of the total crossbred advantage. Just think back 40 years to what the Angus x Hereford cow did to match up the strengths of those two breeds and mask some of the weaknesses of each; that was complementarity!
The formation of composite breed types based on a multi-breed foundation is an attractive alternative to traditional crossbreeding systems. Composite breed types are based on matings among crossbreds of two or more breeds. Once a composite is formed, it can be managed as a straightbred in a one-pasture system with none of the problems associated with small herd size or fluctuation in breed composition.
Comments
Published for the Proceedings, The Range Beef Cow Symposium XIX December 6, 7 and 8, 2005, Rapid City, South Dakota.