EFFECT OF GRAIN OR SILAGE SUPPLEMENTATION ON MEAT QUALITY ATTRIBUTES OF CRYPTORCHID LAMBS GRAZING LUCERNE OR ANNUAL GRASS-CLOVER PASTURES

Objective and subjective tests for quality were performed on the meat from 40 cryptorchid second-cross lambs fed lucerne only (L; n = 8), lu cerne plus an oat grain supplement ad libitum (LO; n = 10), lucerne pl us wilted lucerne silage ad libitum (LS; n = 11), or an oat-lupin grai n (3:1) supplement at 90% of ad libitum while grazing dry summer annua l pasture (OL; n = 11). All carcasses complied with the Elite lamb spe cification of weight >22 kg and GR measurement 6-15 mm. There was no s ignificant difference between groups for hot carcass weight, the mean (+/- s.e) values being 25.1 +/- 0.43, 25.2 +/- 0.36, 25.2 +/- 0.38, an d 25.3 +/- 0.36 kg for L, LS, LO, and OL groups, respectively. When th e GR and fat depth over the eye muscle at the 12th rib were adjusted t o a common carcass weight of 25.2 kg there was no significant differen ce between groups. There was no significant difference between groups for pH, or the colour values a, b*, and L* of the M. longissimus thor acis et lumborum (a is relative redness, b* relative yellowness, and L relative lightness). The shear force values for the loin muscle wer e significantly (P<0.05) greater for lambs from group OL than for thos e from group LO. Cooking loss for the loin muscle was significantly (P <0.05) greater for OL lambs than all other groups. A comparison of the mean values for aroma and flavour showed the lambs from group OL prod uced meat that was considered significantly (P<0.05) less desirable fo r these characteristics, with other groups being similar. Meat from OL -fed lambs was considered oilier and less meaty than meat from lambs f ed the other diets. There was a significant (P<0.05) difference in abs olute scores between panellists, but their ranking was not affected an d there was no panellist x sample interaction. Because many producers use grain supplements such as oats and lupins for finishing lambs on d ry forages, further study is recommended that focuses on the interacti on between supplement and the base forage.