The repeatability of cow performance in beef cattle

The repeatability of cow performance is of special interest to persons engaged in the breeding of beef cattle since the age at which low producing cows can be safely culled from gerd depends largely upon this characteristic. If the repeatability of performance characteristics of the average cow is known a more definite herd replacement program may be followed since the success of selecting breeding females on the basis of production records depends on the correlation of observed and future production.

A greater percentage of the studies concerning the repeatability of cow performance in beef cattle has been with range Hereford cows; however, the reported observations in range herds are in fairly close agreement with the estimates reported for eastern herds. The differences observed between range and eastern cows may be attributed to climatic conditions, herd management, culling practices and grazing facilities.

It is hoped that the results of this study involving this determination of the repeatability of birth and 180 day weights and the type and condition grades at weaning for successive calves from the same cows from herds at the University of Tennessee Agricultural Experiment Stations at Crossville and Greenville, Tennessee, when added to calculation from other workers, will be helpful in indicating the average repeatability for these performance characteristics in beef cattle.