Impact of extended total time off feed on lamb eating quality

Summary

​MSATM guidelines for lamb producers and processors ensure a consistent and predictable quality of lamb meat is produced. However, some prime lamb producers are located at distances or situations that result in feed curfew periods falling outside of the guidelines.  This project was undertaken to investigate alternative pathways for the supply of lamb to MSA specifications and to examine whether there are any negative welfare implications of these alternative pathways.
Lambs from Kangaroo Island (KI) and from within 2.5h travelling time of the processor had objective measurements of the loin (fresh colour, ph-temperature window, ultimate pH) consistently within threshold limits to achieve acceptable eating quality.  There was no difference in shear force (tenderness) of the loin or topside between lamb source.  There was no adverse effect of feed curfew (48h, 76h, 91h) on carcase weight or objective eating quality measurements of the loin.  There was a significant interaction between lamb source and curfew on ultimate pH of the leg, with lambs with longer curfews having lower values.  Lambs from KI were more likely to have dark cutting loins and legs.
None of the welfare indicators (plasma osmolality, urine specific gravity, liveweight loss in lairage, muscle glycogen) were outside normal ranges for healthy sheep, with evidence to suggest that sheep accessed water in lairage.
Extending the feed curfew time of lambs from 48h up to 90h will not detrimentally affect objective measures of eating quality of the loin or affect key animal welfare indicators.