AS-343 June 1966
Review of Lamb Carcass Evaluation
Kenneth J. Drewry, Animal Sciences Department
Sheep industry personnel must continue . to stress the importance of producing the lamb which will be efficient for the producer, economical for the packer, easily merchandised by the retailer and readily purchased by the consumer. Sheep and dairy cattle are the only dual-purpose farm animals. With sheep the relative economic importance of wool and meat production varies by locality, breed and production practices . However, meat production usually accounts for about 75 to 80 percent and wool 20 to 25 percent of the total income from the sheep enterprise. This dual purpose is probably the reason why the sheep industry has never completely defined the "desirable or ideal" sheep.
Average lamb consumption per capita has been essentially four and one-half to five pounds for the past ten years . During this same period, beef consumption increased 20 pounds and pork consumption decreased by seven pounds.
This steady consumption figure for lamb, coupled with an increased economic importance from the "meat-end" of the sheep industry, is one reason for the increased interest in lamb carcass evaluation. A large percentage of the research work performed by colleges and universities on lamb carcass evaluation has been done within the past 10 years . Many of the lamb carcass shows have also developed during this period.
When research results and lamb carcass show rules and regulations are reviewed it is very evident that the "desirable" lamb carcass has not been defined by personnel associated with the sheep industry. Z. L. Carpenter, Texas A & M University, in his
presentation at the Lamb Carcass Evaluation Conference held at Ames, Iowa, in September, 1964, stated that some 12 methods had been used in experimental lamb carcass evaluation research. These methods have included:
1.	Chemical composition
2.	Separable lean, fat and bone
3.	Edible portion
4.	Trimmed retail cuts
5.	Retailed primal cut yield
6.	Retail value
7.	Wholesale primal cuts
8.	Streamlined carcass
9.	Specific gravity
10.	Loin-eye area and fat thickness
11.	Conformation and objective measurements
12.	U.S.D.A, grade
As would be expected, these methods vary in the amount of work involved as well as in their predictive value in identifying the more desirable carcass.
Personnel who pioneered in establishing lamb carcass evaluation shows were forced to draw upon the 12 methods listed above.
The shows had to utilize method (s) which had a high predictive value in identifying the "ideal" carcass, and the procedures for the shows had to be such that large numbers of animals could be evaluated. In many of the shows the lambs were slaughtered, and carcass evaluation measurements were obtained in the facilities of cooperating packers .
Hence, the carcasses had to be easily merchandised after carcass measurements were obtained.
Cooperative Extension Service, PURDUE UNIVERSITY, Lafayette, Indiana