Benchmarking Callipyge Sheep Meat Eating Quality

Summary

A major constraint to the profitability of the sheep-meat industry is the relatively small size and yield of lean muscle mass from carcasses. However, increasing muscling of lamb carcases has been generally associated with adverse effects on meat tenderness. In particular, the Callipyge mutation (in the US), a genetic mutation that is associated with extreme muscling has been associated with toughness. Animals expressing the Callipyge phenotype show a marked difference in carcase composition of 25% more lean mass and 30% reduction in carcase fat. Available taste panel and consumer testing information on Callipyge lamb has used US consumers that typically eat lamb once or less than once per year. 
 This aim of this research was to benchmark Australian consumer acceptability of Callipyge lamb and normal lamb against Australian lamb with industry average muscling or industry leading muscling based on eye muscle depth. This was undertaken using Australian consumers under the established experimental environment utilised by the Australian Sheep Meat Eating Quality program. All sample preparation was performed by Cosign Pty Ltd, with consumer eating quality trial run by Sensory Solutions Pty Ltd. This report demonstrates that Australian consumers rate Callipyge loin samples eaten as grilled steaks as 40% lower quality across tenderness, juiciness, flavour and overall like attributes when compared to loin samples from Australian high muscled lambs and Australian and US normal muscled lambs. This equated to 60% of callipyge loin samples failing consumer expectations for eating quality, compared to a fail rate of approximately 10% in the other groups. Australian consumers also reported smaller reductions in tenderness, juiciness, flavour and overall like attributes in leg (25%) and shoulder (10%) roasts of the Callipyge lamb carcases when compared to the other groups. This equated to approximately 40% of callipyge leg roasts failing consumer expectations for eating quality, compared to a fail rate of less than 20% in the other groups. The difference between Callipyge and the other sample groups in failure rates within the shoulder roasts were not as marked. Despite the marked benefits in carcase composition seen in Callipyge lambs, these results confirm the unsuitability of Callipyge as a production genotype for Australian and international markets for high quality grill and roast cuts.