Weekly genomic-enhanced carcass EPDs are calculated from an integrated analysis of the Beef Improvement Records carcass, ultrasound, growth (weaning weight), and genomic profile databases. The weekly genetic evaluations result in a single EPD for carcass weight, marbling score, ribeye area, and fat thickness. The units of measure for EPDs are in carcass trait format – marbling score, carcass weight in pounds, carcass ribeye in square inches, and carcass fat thickness in inches. Growth (weaning weight), carcass, genomic and pedigree databases are simultaneously combined into one set of genomic-enhanced carcass EPDs for Angus breeding programs. Every Friday morning, the genomic-enhanced NCE EPDs are available at To learn more about genomic-enhanced EPDs, click here.

The carcass and ultrasound data contributing to the evaluation are described in Table 1 and Table 2  with average adjusted measurements.

Ultrasound images incorporated into the carcass EPDs were collected by field technicians certified by the Ultrasound Guidelines Council (UGC). The images were interpreted through one of the American Angus Association's authorized ultrasound processing labs by UGC-certified lab technicians.

Table 1. Angus phenotypic averages of steer and heifer carcasses
        330 < Age < 480        481 < Age < 799
Avg. age at harvest, days4363055459
Adj.2 carcass wt., lb.70684714102
Adj. fat thickness, in..
Adj. ribeye area, sq. in.12.031.3512.141.54
Adj. marbling score6.731.306.351.38
No. of heifers        5,544        6,719
Avg. age at harvest, days4372652445
Adj. carcass wt., lb.79784779101
Adj. fat thickness, in..
Adj. ribeye area, sq. in.12.611.3312.631.44
Adj. marbling score6.231.085.871.27
No. of steers        75,864        27,841
1SD = standard deviation.
2Carcasses were adjusted to 480 days of age at harvest.
Table 2: Yearling Angus live-animal and ultrasound measures
Age, days370263893040438
Gain, lbs/day2.920.691.510.522.840.74
Adj. scan weight, lb.11181398661121102168
Adj. %IMF, %3.821.074.791.374.931.43
Adj. ribeye area, sq. in.12.571.899.761.7312.282.25
Adj. 12-13th rib fat thickness, in..
Adj. rump fat thickness, in..
No. of Animals1,096,919747,60313,015
1SD = standard deviation.

As a review, the scoring system for marbling and its relationship to the USDA Quality Grading System is defined in Table 3. For a carcass to meet Certified Angus Beef (CAB) standards, it must have a Modest ( average Choice) or higher marbling degree, be of "A" maturity (the most youthful classification for beef), 10 to 16 square inch ribeye, less than one inch fat thickness, less than 1,000 pound hot carcass weight and have a fine to medium marbling texture. For more details, go to
Table 3. USDA quality grading system and marbling score.
Quality Grade Amount of Marbling Numerical Score
Prime + Abundant 10.0 - 10.9
Prime Moderately abundant 9.0 - 9.9
Prime - Slightly abundant 8.0 - 8.9
Choice + Moderate 7.0 - 7.9
Choice Modest 6.0 - 6.9
Choice - Small 5.0 - 5.9
Select Slight 4.0 - 4.9
Standard Traces 3.0 - 3.9
Standard Practically devoid 2.0 - 2.9
Utility Devoid 1.0 - 1.9