Effects of feeding ensiled date palm fronds and a by-product concentrate on performance and meat quality of Omani sheep

A study was carried out to investigate the potential use of date palm by-products for feeding Omani local sheep. Thirty-two Omani sheep were fed for 120 days one of four ration combinations of two roughages and two concentrates. The roughages were urea treated palm frond (UTPF) and Rhodes grass hay (RGH). The concentrates were a pelleted commercial cubes (CC) and a concentrate made from local by-products (BC). Experimental measurements included daily feed intakes, bi-weekly body weights, hematological values, apparent digestibility, and carcass and meat quality characteristics. The BC was formulated from 250 ground date fronds, 250 wheat bran, 200 ground Prosopis juliflora pods, 150 barley grain and 120 g/kg dried sardines plus vitamin and mineral additives. The UTPF silage was prepared by ensiling shredded palm fronds in a 30 g/l urea solution for 5 weeks. On dry matter (DM) basis, the BC and CC concentrates contained 179 and 180 g/kg crude protein (CP); 241 and 56 g/kg acid detergent fiber (ADF); 379 and 182 g/kg neutral detergent fiber (NDF); 118 and 73 g/kg ash; 17.9 and 18.3 kJ/g DM gross energy (GE), respectively. The UTPF and RGH contained 85 and 100 g/kg CP; 580 and 370 g/kg ADF; 740 and 614 g/kg NDF; 120 and 95 g/kg ash; 19.2 and 17.3 kJ/g DM GE, respectively. Experimental animals fed the date palm by-products were in good health throughout the trial. In absolute terms, sheep fed the UTPF had lower feed intakes than those fed the RGH but feed intake/body weight (BW) was similar across diet groups (30 g/kg). By-products fed sheep gained less (P<0.05) weight than those fed RGH and CC. The average daily gain was 80, 56, 32 and 10 g/d for the CC + RGH, BC + RGH, CC + UTPF and BC + UTPF, respectively. Feed conversion (kg feed/kg BW gain) was lower for UTPF and BC feeds. Apparent digestibility coefficients for DM, CP, ADF, NDF, ash and DE were lower for UTPF and BC based diets. Feeding UTPF and BC reduced carcass weight, dressing, fat content and carcass measurements. However, feeding CC with UTPF improved sheep performance compared to BC + UTPF. There were no effects of feeding UTPF or BC on meat quality. This experiment indicated that date palm by-products might be used for feeding Omani sheep for maintenance or during times of nutritional shortage frequently experienced in the arid tropics.