Effects of silage based diets on carcass quality of prime lambs.

Abstract

Proc. Aust. Soc. Anim. Prod. Vol. I9 EFFECTS OF SILAGE-BASED DIETS ON CARCASS QUALITY OF PRIME LAMBS F. U. DATTA, R. W GRAHAM and R. H. SOEHARTONO School of Agriculture, Charles Sturt University; and Agriculture Research Institute, Wagga Wagga, N.S.W. 2650. Over fat carcasses have been identified as the major problem in meeting consumer demands for lamb (Currie 1986). Apart from genotype, this trait is dependent on dietary energy and protein (Bass et al. 1990). At present, the practice of finishing carryover lambs on high grain diets is increasing. However, a high energy diet during this period, prior to slaughter, results in an increased level of carcass fatness. Fifty-six first cross Border Leicester x Merino wether lambs (3 1.3 * 0.22 kg) were used to evaluate the effects of subterranean clover silage supplemented diets (Table 1) on carcass characteristics. The lambs were randomly allocated to 8 treatment groups (7 lambs/group). All lambs were individually penned in an animal house and were fed ad Zibitum. Experimental animals were slaughtered at approximately 45 kg (68 days for treatment groups and 104 days for the control). Lambs on high grain diets were introduced to concentrates over a 14-day period. Hot carcass weight (HCW), fasted liveweight (FLW), tissue depth over the 12th rib 110 mm from the midline (GR) were measured. Mean values for FLW and adjusted mean (& s.e.) for HCW and GR are presented in Table 2. Table 1. The percentage of components in experimental diets All diets supplemented with vitamin-mineral premix Analyses of covariance indicated a dietary effect on HCW, however, there was no dietary effect on carcass fatness as indicated by GR. These results are in agreement with Black (1983), who stated that the extent to which body composition can be manipulated by dietary means is relatively small. BASS, J. J., BUTLER-HOGG, B. W. and KIRTON, A. H. (1990). In ` Reducing fat in meat animals.' (Eds J. D. Wood and A. V. Fisher.) p.170. (Elsevier: London.) Implications of Developments in Meat Science, Production and Marketing for Lamb BLACK, J. L. (1983). In ` Production Systems.' Paper 24 APC Workshop, (Eds L. P Thatcher and D. C. Harris.) (Orange: N.S.W.) CURRIE, J. R. (1986). Proc. Aust. Sot. Anim. Prod. 16: 95. 170