Carcass composition of the South Australian Merino and its crosses with the Booroola and Trangie Fertility Merino

Abstract

South Australian medium-wool (M), non- Peppin medium-wool Booroola (B) and Peppin medium-wool Trangie Fertility (TF) Merino rams were joined to M ewes at Turretfield Research Centre, South Australia, in 2 years. Carcass composition was assessed in the ewe and wether progeny at 2 mean slaughter liveweights, viz. 24 and 38 kg. When adjusted to the same carcass weight, B x M had 13% more carcass chemical fat, 15% more subcutaneous fat, 6% less bone and the same lean tissue as M. The same result was observed for TF x M in relation to M in year 2. However, TF x M had more lean and the same amount of subcutaneous and chemical fat as M in year 1. Within the Booroola strain, there were no differences between offspring from 3 sires with genotype FF and the 1 sire with + + for any of 5 variables analysed. We conclude that crossing the Booroola with the South Australian Merino produces carcasses with the same amount of lean tissue, less bone and more fat when compared at the same carcass weight. The rank of TF x M with the other strains for the major carcass components remains obscure owing to a strain x year interaction.