SUPPLEMENTATION OF COWPEA (Vigna unguiculata) HAY, WHEAT BRAN AND THEIR MIXTURES TO BEGAIT SHEEP FED GRASS HAY IN WESTERN TIGRAY, ETHIOPIA: EFFECTS ON GROWTH PERFORMANCE, CARCASS CHARACTERISTICS AND SKIN QUALITY

Abstract

Twenty five yearling male Begait sheep with initial body weight (BW) of 28.02± 1.49 (mean ± SD) were used to evaluate the effect of supplementation of cowpea (Vigna unguiculat) hay (CPH), wheat bran (WB) and their mixtures to sheep fed grass hay (GH) on feed intake, digestibility, average daily gain (ADG), carcass characteristics, skin quality and economic feasibility. Experimental sheep were blocked in to five blocks based on initial body weight and randomly assigned to the five treatments. Treatments were ad libitum feeding of GH and supplemented with 300g CPH, 225g CPH +75g WB, 150g CPH +150g WB, 75g CPH +225g WB and 300g WB DM/day, respectively for T1, T2, T3, T4 and T5. Water and common salt blocks were freely available to sheep. The experiment consisted of 90 days and 7 days of feeding and digestibility trials, respectively and carcass evaluation and skin quality determination at the end. The crude protein (CP) content of GH, CPH and WB were 5.46%, 17.15% and 16.5%, respectively. Total DM intake was 687.1, 669.4, 719.4, 631.0 and 673.47 ± 6.8 PSE gd-1 for T1, T2, T3, T4 and T5, respectively and significantly higher (p<0.001) and lower (p< 0.001) for T3 and T4, respectively and intermediate for others. Digestibility of CP was 58.8, 66.1, 70.9, 62.9 and 65.2 ± 1.1 PSE for T1, T2, T3, T4 and T5, respectively was higher (P<0.001) for T3. The ADG was 36.4, 43.6, 52.9, 43.1 and 42.4 ± 1.3 PSE gd-1 for the sheep in T1, T2, T3, T4 and T5, respectively was higher (p<0.001) for T3. Consequently, the value for hot carcass weight (HCW) was significantly higher for T3 (12.92) than T2 (12.61), T1 (11.92), T4 (11.96) and T5 (12.42 kg) and dressing percentage (DP) on slaughter and empty BW basis were higher (p<0.05) for T3 (42.04 and 58.66%) and T2 (41.91and 57.68%) than T1 (40.89 and 55.62%) and T4 (40.87 and 56.18%). Absence of statistical difference (p>0.05) in chemical constituents and significant difference in physico-mechanical qualities of the skin were observed among the treatment groups. The values for tensile strength (19.67, 22.44, 21.40, 20.0 and 20.40N/mm2 ± 0.3PSE), elongation percentage (55.21, 60.72, 56.11, 45.99 and 53.08% ±1.4 PSE) and tear strength (68.08, 85.49, 81.29, 60.41 and 73.89 N/mm ± 2.5PSE) for T1, T2, T3, T4 and T5, respectively was significantly higher in T2 and T3 than the rest treatments. The net return (NR) (179.08 ETB), and marginal rate of return (MRR) (125.42 ETB) were also higher for T3 than others. Therefore, the study suggested that feeding equal amount of cowpea hay to wheat bran improved sheep performance and it is crucial to alleviate shortage of feed with reasonable cost in the study area