American consumers have reduced their consumption
of fat from animal products as they have become
more diet and health conscious (NRC, 1988). Recognizing
this trend, the American Sheep Industry
Council has promoted a certified lean lamb classification
and has been instrumental in the implementation of a revised USDA lamb yield grading system to
encourage production of leaner lamb through either
genetic or management means, and lamb processors
have been challenged by financial incentives to produce
leaner lambs. The identification and genetic
mapping (Muggli-Cockett et al., 1993) of a mutation
causing extreme muscling in sheep appears to provide
tremendous potential for production of leaner lamb
carcasses. Limited information is available in the literature
concerning the effects of this gene (termed
‘Callipyge’). The objective of this study was to evaluate
the effect of the Callipyge (CLPG) gene on carcass