The impact of lean meat yield on Australian lamb eating quality is partially driven by intramuscular fat.

The impact of increasing lean meat yield (LMY) on consumer eating acceptance and its association with intramuscular fat (IMF) of lamb products was evaluated. Consumer sensory scores (overall liking, tenderness, juiciness, flavour liking) of the loin and topside were obtained from 3119 lambs, in addition to the knuckle, leg, outside, rack, rump and shoulder from a subset of these animals (n = 824). LMY indicators included GR tissue depth (measured 110 mm from dorsal midline of 12th rib), whole carcass and section (fore, saddle, hind) computed tomography (CT) lean% and cut weight of the loin and topside (as a percentage of the total carcass weight). Loin IMF was measured on all animals, with topside, outside, rump and shoulder IMF obtained from a subset of animals. Linear mixed models demonstrated a reduction in eating quality with increasing LMY in all cuts (P < 0.05) except the knuckle and leg. The impact on eating quality varied depending on the method used to estimate LMY, with the strongest association observed when using CT lean% measures, particularly section CT lean% from which the cut was taken. The effect of LMY on consumer eating quality was fully driven by IMF within the loin and rump cuts (P > 0.05) but only partially in the rack, outside and shoulder (P < 0.05). Results confirm the importance for simultaneous selection of LMY and IMF as key drivers of sheepmeat eating quality and the importance for the inclusion of on-line predictions of LMY in eating quality grading systems.