Ah. Kirton et al., A COMPARISON BETWEEN 15 RAM BREEDS FOR EXPORT LAMB PRODUCTION .1. LIVEWEIGHTS, BODY COMPONENTS, CARCASS MEASUREMENTS, AND COMPOSITION, New Zealand Journal of Agricultural Research, 38(3), 1995, pp. 347-360
Results on the body and carcass composition of 7885 lambs sired by 371
rams of 15 different breeds mated to Romney cast-for-age ewes are giv
en. Trials were run at the Ruakura Agricultural Centre and the Manutuk
e Research Station from 1963 to 1972. Lambs of the different breeds we
re slaughtered at the same average age so that differences between bre
eds/crosses in liveweight and carcass weight reflected differences in
growth rate. Ranked from heaviest to lightest mean age-adjusted carcas
s weights, lambs sired by the Dorset Horn, Poll Dorset, Hampshire, Bor
der Leicester, Suffolk, Dorset Down, South Suffolk, and South Dorset D
own produced the heaviest carcasses, and those sired by the Cheviot, S
outhdown, English Leicester, and Ryeland were intermediate. The Lincol
n, Merino, and Romney sired carcasses were lighter. The longer-woolled
Romney, Merino, and Lincoln had lowest dressing out percentages based
on full liveweights and the short finer-wooled breeds such as the Sou
thdown, Dorset Down, and Poll Dorset/Dorset Horn dressed 2-3% higher.
When compared at the same carcass weight, lambs sired by the Southdown
followed by the Ryeland had the fattest carcasses and those sired by
the Suffolk, Cheviot, and Dorset Horn produced the least fat, leanest
carcasses. The Southdown, Dorset Horn, South Dorset Down, and Poll Dor
set crosses had the largest eye muscle areas for carcasses of similar
weight.