USDA Slaughter Animal and Carcass Grades


Objectives:

(1) To translate the evaluation of age, weight, sex, fatness and muscling into readily usable market descriptions.
(2) To determine how and why grades of slaughter animals and carcasses are important to animal agriculture.
(3) To demonstrate the factors involved in quality and quantity evaluations of animals and carcasses.


Grades -- Groups of livestock of similar market desirability in terms of predictions of the type of carcass they will provide.

Carcass value depends upon:

Age

Weight

Sex

Fatness

Muscling

Of these, weight and sex are easily described, but age, fatness and muscling have endless combinations.

It became obvious in the early 1920's that some common terminology had to be developed to facilitate market news reporting and transactions sight unseen.

Estimated palatability (words)
Beef
Pork
Lamb
Prime
U.S.
Prime
Choice
U.S. Utility
Choice
Select Good
Standard Utility
Commercial Cull
Utility
Cutter
Canner

Estimated cutability (numbers)
Beef Pork Lamb
1 1 1
2 2 2
3 3
4 4
5 5

	

Grading concepts ---> Once the purpose is defined, specific traits in carcasses can be used to identify and stratify carcasses into homogeneous groupings.

Heterogenous supply ---------------------------> Homogenous groups
A, B, C, D, etc.

Dichotomous -- two categories

Acceptable

Unacceptable

Hierarchical -- several entities arranged in a graded series

Superior

Good

Average

Inferior

Original concepts of beef carcass grading

Group for elite consumers where taste was the only issue

Groups for retail consumers with different priorities for taste and leanness

Groups for further processed (ground, comminuted or prepared beef items)

Thus, Prime was identified for the elite consumers, Choice, Select and Standard for retail consumers, and Commercial, Utility, Cutter and Canner for manufacturing beef.

Cutability grades were developed in the 1960's as more accurate ways to segment carcasses based on the yield of closely trimmed, boneless retail cuts because it was possible to have very lean and very fat Choice carcasses. In the cutability systems for beef, pork and lamb, the following are important measures that are closely related to carcass composition:

Measurement Beef Pork Lamb
Size Carcass weight None None
Muscling Ribeye area Muscling score None
Trimmable fat Fat thickness, 12th rib Backfat, last rib Fat thickness, 12th rib
Internal fat Kidney, pelvic & heart fat None None


	

Fatness -- as fatness increases, retail cut yield decreases

Muscling -- as muscling increases, retail cut yield increases


Review of Material -- What the student should know:

(1) The concepts of grades.

(2) Differences in dichotomous versus hierarchical grading.

(3) Why compositional grades were developed.


Links to related sites on the Internet

Value-Based Marketing of Beef
The Role of USDA's Beef Grading Program in the Marketing of Beef


Meat Science at Texas A&M University

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