MEAT QUALITY OF CRYPTORCHID LAMBS GRAZING EITHER DRYLAND OR IRRIGATEDPERENNIAL PASTURE WITH SOME SILAGE SUPPLEMENTATION

The meat quality of lambs grazed on perennial pasture (ryegrass Lolium perenne, cocksfoot, Dactylis glomerata and white clover Trifolium rep ens) was examined in three treatments, group 1 (S) lambs were grazed o n dryland pasture for 30 days and then offered a supplement of pasture silage ad libitum until slaughter, 30 days later (n = 21). Lambs in g roup 2 (P) were grazed on dryland pasture throughout (n = 28) and thos e in group 3 (IP) on irrigated pasture (n = 28). Lambs in group IP had a significantly (p < 0.001) heavier pre-slaughter liveweight and hot carcass weight than lambs in the other two groups. There was no signif icant difference (p < 0.05) in fatscore between groups or in GR when a djusted to a common carcass weight. For cold carcass weight (reduced s ample) IP lambs were still significantly heavier than those from group P, but no different to those from group S (n = 15, 15 and 10, respect ively). There was no significant difference between groups for measure s of fatness or for m. longissimus thoracis et lumborum (LL) area when adjusted to a common carcass weight of 23.6 kg. There was a significa nt difference between (p < 0.001) treatments for pH, group P carcasses having higher pH values for the LL muscle, with no treatment effect o n m, semimembranosus (SM) pH. Differences between groups for meat colo ur values (L, a*, b*) showed no consistent trend and there was no sig nificant difference (p > 0.05) between groups in tenderness of the LL and SM muscles as indicated by shear force values. Aroma of the loin m eat from pasture-fed lambs (P) was considered significantly (p < 0.05) stronger than from lambs in groups S and IP (n = 6, all groups) and t he flavour of samples from lambs in group P was significantly (p < 0.0 5) stronger than from lambs in group IF. Overall there was no signific ant (p < 0.05) difference in acceptability between groups. The results indicate that consumers would be unlikely to detect the differences i dentified by the panel and that pasture silage will nt have an adverse effect on lamb eating quality. (C) 1998 Elsevier Science Ltd. All rig hts reserved.