4.1.5: Growth rate is important to producers of beef cattle, but it does not take composition of gain into account. It is tempting to combine these two factors into a single measure such as "retail product per day of age." Such a measure is useful among animals of similar ages which were raised under similar feeding regimes or among animals of similar composition but which differ in age.

However, if animals differ widely in age or are raised under different feeding regimes, the comparisons give unwarranted advantage to younger animals and to animals on the more rapid development regimes. Under these conditions, it might be preferable to rank yield grade, quality grade, and growth rate (based on live or carcass weight) separately. An index of overall merit can then be developed to combine these measures. Breed associations or breeders should determine the weighting of factors in the index that are appropriate for their production programs.

4.2: Obtaining Carcass Evaluation

Persons desiring carcass data should plan in advance. Identification of the cattle to be slaughtered is a must if data on individual animals are desired. Although many research and Extension personnel are qualified and can collect carcass data, their services are not always available. In most cases, if requested, data can be collected by a USDA Agricultural Marketing Service (AMS) Meat Grading and Certification Branch employee.

Also, contact a cooperating packer well in advance. An attitude of ‘How can we obtain the carcass information that is important to my breeding program without seriously disrupting your operation?" will usually be more successful than demanding the packer’s cooperation and the grader’s time at your convemence,

USDA programs are available for carcass data collection. The USDA Beef Carcass Evaluation Service is much to be preferred. The USDA Beef Carcass Data Service (orange ear-tag program) is no longer recommended as a reliable means to collect carcass grade information.

4.3: USDA’S Beef Carcass Evaluation Service

This service is provided on a fee basis and may be requested from the nearest USDA Meat Grading and Certification Office. This office will need to know the location where cattle will be slaughtered; the number of animals involved; data desired; the approximate time of slaughter; and the person to be billed for the service.

Animals must be identified with eartags, ear tattoos, or backtags.

Transfer of identification from live animal to dressed carcass requires communication and close cooperation between the packer, producer, meat inspector, and grader. Great care must be given to this procedure or all subsequent data may be meaningless. This is especially true when individual animal data are needed,

After the carcass is chilled, the grader will record the information requested for each animal on a USDA Beef Carcass Evaluation Report (a fictionalized sample in Fig. 41) which the grader will forward to the producer or feeder requesting the service. The fee will vary depending upon the amount of information requested and expenses incurred in identification transfer and by the grader, such as travel. Breeders who consider carcass data as an essential part of their performance program should use the USDA Beef Carcass Evaluation Service.

A list of Main Station Offices of the USDA Meat Grading and Certification Branch and the states served by each is included at the end of this section.

4.4: Main Station Meat Grading and Certification Branch Offices and the States served by each

Main Station Supervisor
USDA-AMS
205 E. 5th Ave., No. 13222
Amarillo, TX 79120
8--735-1264 (FTS System)
806/372-7361 (Commercial)
KS, NM, OK, TX

Main Station Supervisor
USDA-AMS
Building 7, Section A
5600 Rickenbacker Road
Bell, CA 90201-6490
213/269-3025/28 (Commercial)
AZ, CA, HA, NV, OR, WA

Main Station Supervisor
USDA-AMS
800 Roosevelt Rd.
Building A, Suite 30
Glen Ellyn, IL 60637-5832
708/790-6900 (Commercial)
IA, IL, IN, MN, MO, WI

Main Station Supervisor
USDA-AMS
100 W. Pioneer Parkway
Suite 212, Center Street Court
Arlington, TX 76010-6177
8--334-7820 (FTS System)
817/885-7820 (Commercial)
AR, AZ, FL, GA, LA, MS, NC, OK, PR, SC, TX

Main Station Supervisor
USDA-AMS
400 Livestock Exchange Building
Denver, CO 80216-2139
8--564-7676 (FTS System)
303/294-7676 (Commercial)
CO. ID, MT, NE, SD, UT, WY

Main Station Supervisor
USDA-AMS
827 Livestock Exchange Building
Omaha, NE 68107-2603
8--864-4635 (FTS System)
402/731-2014 (Commercial)
IA, KS, ND, NE, SD

Main Station Supervisor
USDA-AMS
2017 Watt St., Research Park
Princeton, NJ 08540-1553
8--483-2309 (FTS System)
609/921-3305 (Commercial)
CT, DE, IN, KY, MA, MD, MI, NH, NJ, NY, OH, PA,
RI, VA, VT, WV

4.5: Application of Carcass Evaluation to Improvement Programs

There is considerable evidence that the beef cattle industry is moving into an era of specification production to meet the current demands of the consuming public. To produce a nutritious, high quality uniform product for the consuming public, considerably more carcass information needs to be available on various sire lines within a breed.

The following proposal outlines a design to help purebred producers and commercial cattlemen identify those sire lines that can allow the industry to produce the type of beef product that the consuming public desires.

4.3.1: Data Collected and Eligibility. Following the arrival of the cattle at a commercial or private feedlot there would be an approximate 21-day adaptation period before the start of the official feeding test. It is suggested that all steers be routinely processed upon arrival and be pre-conditioned and weaned at least 30 days prior to consignment.

It would be our suggestion that tbe progeny data be collected on steers. However, heifer data can also be useful. For a test to be a sire evaluation, with data qualifying for a breed association sire summary for carcass traits, at least two sires must be represented with a minimum of 5 head and preferably 20 head per sire consigned. In order to evaluate sires within a breed, one of the sires used must be a reference sire. If no reference sire is used across herds, the comparison will be within herd. To be sure that your carcass data will qualify for a national cattle evaluation with your respective breed associations, it is encouraged that you call your national association prior to consigning cattle to a test.

For sire progeny to be considered a contemporary group, the following criteria must be considered:

a. Calves from first calf heifers should be treated as a separate contemporary group, unless common reference sires are used on both cows and heifers.

b. Either heifers or steers could comprise a contemporary group. However, a contemporary group made up of heifers cannot be compared to a contemporary group comprised of steers unless a common reference sire is represented in each group. In other words, we can compare sires A, B, and C, even though A had only heifer calves and B had only steer calves as long as sire C had an adequate number of progeny represented in each sex contemporary group.

c. The breed of dam should be the same for each contemoraiy group. If not, sire and reference sire matings should be at random.

d. All animals within a contemporary group must be born within a 90-day period to be evaluated against each other.

e. It is recommended that yearling ultrasound carcass measurements used in National Cattle Evaluation be taken when animals are between 320 and 450 days of age.

All the data collected should be on an individual basis. Upon arrival, the cattle should be frame scored and ultrasonic equipment used to determine on-test fat cover.

During the duration of the trial, rate of gain should be recorded with the cattle slaughtered when all of the contemporary group consigned by an individual reach an average compositional end point (fat thickness) and do not exceed an average live weight appropriate for the biological type as follows:

The program should be in a position to cooperate with a national or state breed association in developing guidelines specific for their needs. For instance, if they have a4esired compositional endpoint or end weight, there needs to be flexibility in the program to accommodate these needs. The number of cattle needed to adequately evaluate a sire genetically could be determined by the breed association.

4.5.2: Data Collection - Options.

Option A: Feedlot Performance and USDA Carcass Grading Data

Option B: Warner-Bratzler Shear Force Analysis

If the owner of a beef sire desires an objective evaluation of tenderness on progeny it would be advantageous if a Warner-Bratzler analysis could be made.

4.6: Ultrasound Proficiency Guidelines

In recent years the refinement of ultrasound procedures and technology has focused on an exciting new era of identifying genetic merit in beef cattle with particular regard to carcass value. Increased interest and industry needs prompted the Beef Improvement Federation to consider guidelines for training and evaluating proficiency of ultrasound technicians. Guidelines intended to provide a uniform method in the collection of ultrasound data are being developed by an ad hoc Implementation Committee. When these are complete they will be published.