Some effects of nutrition and castration on meat production from male Suffolk cross (Border Leicester-Romney cross) lambs

Abstract

Meat quality of Suffolk cross (Border Leicester-Romney cross) lamb carcasses was assefsecl by taste panels and by objective measures of shear force and sarcomere length. In one experiment the quality of meat from lambs raised on pasture was at least as good as that from lambs receiving either barley-based pellets or a diet containing high levels of protected polyunsaturated fatty acids (PPF A) for an ex:ended period (mean of 112 days). The PPFA-fed group produced meat significantly tougher and less juicy than did pasture-fed lambs; its least acceptable characteristic was flavour. Some sets of measurements indicated that barley feeding slightly decreased tenderness, flavour, and juiciness relative to pasture feeding. Carcass fat from the PPFA-fed lambs contained an average of 22.9% linoleic acid; non-carcass fat depots had higher levels. The ratio oleic: stearic acid was higher in fat from lambs fed barley than from those fed pasture. A second experiment showed little difference between meat quality from rams and wethers raised on pasture, the only significant effect being a slightly higher shear force for M. semimembranosus of rams. Changes in meat quality with increasing weight and age were small; shear forces generally increased, and overall acceptability was highest at an intermediate carcass weight of about 20 kg in one experiment.