Carcass Cuts & Fabrication

When you go to the grocery store and see that meats have a grade stamp on the package, its important to know what the stamp means. The United States Department of Agriculture uses a dual grading system on beef carcasses. More than 95% of beef cattle receive USDA grades.

USDA grades are voluntary and are divided into market classes. The classes are; heifer, cow, steer, bull and bullock. And a stag class can be used, which is a bull that has been castrated. There are yield grades which measure the amount of fat, lean and bone in the carcass. Yield grades are often referred to as cutability. And quality grades which are an evaluation of consumer palatibility characteristics.

A USDA grader assigns either as yield or quality grade to beef carcasses post harvest. Ultrasounds have also been put into play when determining subcutaneous fat and carcass grade. When 4-H/FFA kids show livestock at county fairs, there is sometimes a carcass class and an ultrasound is used to determine grading.

Carcass weight is the most important factor in determining the value of a carcass when cattle are bought or sold. A range has been outlined by the National Beef Quality Audit as the target for carcass weight for 650-850 lbs. Final carcass quality grade is determined by maturity and marbling. Quality grading is evaluating factors that affect eating quality and desirability. The quality grade stamps are then divided into four different categories of Prime, Choice, Select and Standard.

There are defects that can arise in the carcass such as dark cutters. Dark cutting meat is noticed by oclor ranging from a dark red to black with sticky texture and a high water holding capacity. It has a shorter shelf life than normal beef and is often rejected because of the color. Blood splash defects is hemorrhaging with the muscles of a carcass. Blood splash is the result of high blood pressure when the capillaries rupture. Calloused ribeye defect is the result of a callus or section of fatty tissue within the muscle because of steatosis of longissimus muscle. Another defect is bruises when trim loss occurs because of fecal contamination or deep tissue bruising or abscesses. In 2005, the National Beef Quality Audit reported that 35.2% of carcasses had a bruise defect.


Sources:
Field, Thomas G. Beef Production and Management Decisions. Ed. Jill Jones Renger and Vernon Anthony. 5th ed. Upper Saddle River: Pearson-Prentice Hall, 2007. Print.

Parish, Jane A., Justin D. Rhinehart, Dr, and James M. Martin, Dr. Beef Grades and Carcass Information. N.p.: Mississippi State University Extension Service, 2009. Print.