AS-331 July, 1965
Beef Performance Testing-Questions and Answers
Lowell L. Wilson, K. G. MacDonald, H. H. Mayo and K. J. Drewry, Animal Sciences Department
Beef cattle performance testing is not new; it has been done on a limited scale for many years . However, with changing market demands and feeding systems and decreasing profit margins, beef cattle performance testing is increasing in importance. Most of the State Extension Services and Breed Associations are presently offering performance testing programs . Some of the more commonly asked questions about performance testing are answered in this publication.
3.	Who can test?
Any purebred or commercial breeder.
4.	What traits are considered?
The first step in the program includes weaning weights and conformation scores collected between 150 and 250 days of age.
An adjusted 205-day weaning weight and daily gain is calculated. Weaning weight and conformation score are then combined into an index which gives equal emphasis to each trait.
1.	What is performance testing?
It is a simple, accurate method of obtaining systematic records on the production of each animal in the breeding herd. These records help the breeder decide on the true breeding value of each calf, cow and bull in the herd.
2.	What research is there to support a performance testing effort?
Research conducted over the past 40 years has definitely shown that most of the important beef cattle traits are moderately to highly heritable. This means that extensive use of performance records can improve the profits from beef cattle through selection for those traits which can increase the efficiency of producing quality beef.
Yearling (12 to 13 months) weights and scores should be obtained on bulls, heifers, and steers. An adjusted 365-day weight is then calculated by combining the adjusted post-weaning daily gain and 205-day adjusted weight.
Carcass evaluation should also be a part of the program. Carcass information on at least 8 steers from each herd sire should be collected. Carcass measurements should include carcass weight, USDA conformation, quality and final grade, loin-eye area, fat thickness and estimated or actual kidney fat.
5.	What adjustment factors are used?
Weaning weights are adjusted for age of calf, age of dam and sex of calf. This allows
Beef Section • Animal Sciences Department Cooperative Extension Service, PURDUE UNIVERSITY, Lafayette, Indiana