Date of this Version
United States Department of Agriculture, Agriculture Research Service, ARS-1, April 1984.
A vast array of both resources and cattle breeds are available for beef production in the United States. Although feeding concentrates has provided for a relatively high degree of uniformity in the growing-finishing segment of beef production, resources used for cow-calf production have remained and will continue to remain very diverse. In the United States, stocking rates range from one cow per 2 acres or less to only one cow per 300 or 400 acres because of differences in climate, land, and feed resources.
The germ plasm base for beef cattle production in North America was broadened considerably during the 1970.s, primarily, as a result of the introduction of new breeds of European origin made possible by the development of appropriate quarantine facilities and procedures by Agriculture Canada. The newly introduced breeds, in addition to those already available, provide a wide range of performance characteristics in beef cattle.
In 1969, the Roman L. Hruska U.S. Meat Animal Research Center implemented a program to characterize a broad range of biological types of cattle as represented by breeds that differ widely in characteristics such as growth rate, carcass composition, mature size and milk production level. The primary objective was to characterize breeds representing diverse biological types for the full spectrum of traits relating to beef production. The breeds used in this program have been classified into six different biological types based on the criteria of (1) growth rate and mature size, (2) lean to fat ratio, (3) age at puberty and (4) milk production (table 1).