Skip to main content
ARS Home » Pacific West Area » Dubois, Idaho » Range Sheep Production Efficiency Research » Research » Publications at this Location » Publication #125519
Title: GENETIC INFLUENCES ON CARCASS MERIT OF SHEEP

Author
item COCKETT, NOELLE - UTAH STATE UNIVERSITY
item SNOWDER, GARY

Submitted to: American Society of Animal Science Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/24/2001
Publication Date: 12/1/2001
Citation: Cockett, N.E., Snowder, G.D. 2001. Genetic influences on carcass merit of sheep. Journal of Animal Science 79 (Suppl. 1):99.

Interpretive Summary:

Technical Abstract: Sheep numbers have decreased from nearly 30 million head in the early 1960s to 7 million head in 2000. Total production of lamb and mutton has not declined as sharply because of an increase in lamb carcass weight. From 1960 to 2000, the average lamb carcass increased from 22 kg to 31 kg. This change in carcass size .is in part the result of improved feed management and an increase in mature size due to direct genetic selection and the use of large terminal sire breeds. Also, lambs are now frequently over-finished because the profit margin often favors larger animals and packers discount only extremely heavy lambs. Heavier carcasses have resulted in increased fat thickness, with the average carcass now exceeding recommendations by the American Sheep Producer Council s Consumer Acceptability Task Force for fat depth. It is possible to produce heavier carcasses with lean lamb characteristics using later maturing breeds, but current production systems have not capitalized on this opportunity. The proportion of lean meat cuts has remained constant in heavier carcasses, except in callipyge and Carwell animals. Lambs expressing these phenotypes have 30 and 8% increases in lean meat, respectively, with associated decreases in fat of 8 and 0%, respectively. However, almost all studies have found decreased tenderness of the callipyge loin. A similar effect on tenderness has not been reported for Carwell carcasses. Consumer consumption of lamb continues to fall, with annual per capita consumption of lamb and mutton dropping from 2.3 to 0.5 kg over the 1960 to 1997 time period. Studies of consumer preference indicate a lamb product with reduced fat and less intense flavor would be more appealing.