EFFECT OF ROUGHAGE TO CONCENTRATE RATIO ON PERFORMANCE AND CARCASS CHARACTERISTICS OF LOCAL LAMBS IN THE UNITED-ARAB-EMIRATES

Sixteen local ram lambs (18 +/- 1.25 kg live weight) were divided rand omly into four equal groups. Each group was offered ad libitum one of the following roughage: concentrate (R : C) ratios 100:0; 60:40; 40:60 ; and 20:80. Two lambs from each group were slaughtered after 3 months of feeding and the other two at the end of the trial (after 4 months) . Average daily gain (P < .0001), dry matter intake (P < .0249) and fe ed conversion ratio (P < .0004) were significantly affected by R : C r atio, Lambs receiving 60 or 80% concentrate consumed more feed, gained more weight, and converted feed more efficiently compared to the othe r two groups. The group fed no concentrate (100% R) gave the poorest p erformance. Slaughter weight (SW) (P < .05), hot carcass weight (HCW) (P < .006), and dressing percentage (DP) (P < .002) were significantly influenced by R : C ratio. Groups that received 60 or 80% C had the h ighest SW, HCW and DP. Performance of lambs on 100% R was the poorest. Roughage : concentrate ratio had no significant effect on carcass tra its or composition, except percent bone in the ribs cut (P < .03) was lower in animals fed 60 or 80% C (by 37 and 37.5%, respectively) compa red to the group fed 100% R. Inclusion of concentrates improved signif icantly feedlot gain, feed conversion efficiency and carcass character istics of local lambs. There was no advantage to extending the feeding period after 3 months.