Abstract

Leg and shoulder composition (fat, muscle and bone) and some linear fat and muscle distribution measurements were taken on 458 lambs produced by 39 strains and breeds of ram born in 1992, 1993 and 1994. Lambs were either Romney or Romney-cross. Texel-cross lambs had the highest proportion of muscle in the leg and shoulder cuts with the Poll Dorset-cross lambs having a similar amount. Southdowns, American Suffolks and Romney strains had least muscle, and apart from the American Suffolk, also had most fat. The fat selected Southdown-cross had the highest % carcass fat. There was no significant difference between any of the sire groups in the proportion of the major defatted leg primal cuts. All genotypes had a similar leg muscle cut distribution, breed differences being only in the relative proportions of muscle to fat and bone. The Texel-cross had the highest weight (at the same carcass weight) of psoas muscle and the ultrasonically selected Poll Dorset progeny had the highest proportion of measured lean as longissimus muscle.

AH, Kirton, DM Duganzich, GJK Mercer, JN Clarke, JL Dobbie, and JA Wilson

Proceedings of the New Zealand Society of Animal Production, Volume 57, , 267-270, 1997