The effect of lairage time on consumer sensory scores of the 'M.longissimus thoracis et lumborum' from lambs and lactating ewes

The aim of this study was to determine whether lairage time influenced consumer sensory scores of the eating quality of lamb and mutton. Commercial consignments of lambs and ewes were subjected to 3 different lairage periods (slaughter on arrival, slaughter after 1 day or slaughter after 2 days in lairage) at one site in Victoria (experiment 1) and another site in Western Australia (experiment 2). In experiment 1, 3 sucker and 3 carry-over lamb consignments, each consisting of 36 lambs, were sourced from a public saleyard. In experiment 2, 3 ewe and 3 lamb consignments, each consisting of 150 animals were sourced directly from the farm of origin. There was no primary effect of lairage time on consumer sensory scores of the 'M. longissimus et lumborum' from either lambs or ewes at the 2 locations. Sucker lambs were tenderer than carry-over lambs in experiment 1. There was an interaction between age class and lairage time for tenderness in experiment 2, such that lamb meat was tenderer than ewe meat when slaughtered after 1 day in lairage. Ewes produced loins with shorter (0.6 μm, P<0.05) sarcomere length, higher (4.9%, P<0.05) intramuscular fat percentage and darker (P<0.05) meat colour compared with those from sucker lambs. Hue angle was higher (2°, P<0.01) for meat from sheep killed after 1 day in lairage compared with meat from sheep killed on arrival or after 2 days in lairage in both experiments.