Meat quality of wether lambs grazed on either saltbush (Atriplex nummularia) plus supplements or lucerne (Medicago...

The meat quality of 42, 8 month-old cross-bred wether lambs that had been grazed on either predominantly saltbush (Atriplex nummularia) and supplemented with pasture hay (n=14) or oat grain (n=14) for 68 days was compared to lambs grazed predominantly on lucerne (Medicago sativa; n=14). The lambs used in the study ranged in un-fasted liveweight from 44.5 to 63.6kg pre-slaughter. There was no significant (p>0.05) difference between the treatments for liveweight, but there was a significant (p<0.05) treatment effect on hot carcass weight with those from the saltbush/hay group (SH) being lighter than those from the lucerne group. When the carcass measures of fatness or m. longissimus thoracis et lumborum area were adjusted to a common carcass weight of 22.4kg there was no difference between groups. There were no significant differences (p>0.05) between groups for pH or colour values (where L* indicates relative lightness, a* indicates relative redness and b* indicates relative yellowness). There was no significant difference (p>0.05) between groups for b(2)* values of subcutaneous fat. Treatment had a significant effect on aroma strength (p<0.05), samples from lambs in the SH group (n=10) and those in saltbush/grain (SG) group (n=10) having a stronger aroma than those from lambs grazed on lucerne (L; n=10). No treatment effect for liking of aroma was found. Flavour strength was not significantly (p>0.05) stronger for samples from groups SH and SG than for samples from group L. There was no effect of treatment on tenderness or juiciness and overall panellists ranked the samples similarly for acceptability. Finishing lambs on saltbush and either supplemented with hay or grain as used in this experiment did not present any apparent meat quality problems compared to lucerne fed lambs.