Abstract:
A study was conducted to evaluate the effect of feeding kocho waste,“dupo” (scraped pseudostem fermented in a pit as upper cover of whole kocho) as a substitution of energy portion of concentrate mixture (ECM, that is 2:1 ratio of maize and wheat bran) on feed intake, digestibility, live weight gain, carcass characteristics, meat quality and economic benefit of Harerge Highland sheep fed a basal diet of natural grass hay. Twenty-four yearling intact Harerge highland sheep with initial body weights (IBW) of 16.29±2.08kg (mean±SD) were assigned to four dietary treatments in a completely randomized block design. The experimental sheep were blocked into six blocks of four animals based on their initial body weight (IBW) and randomly assigned to one of the four treatments within a block. The treatments were 75% ECM + 25% NSC (T1), 50%ECM + 25% kocho waste (dupo) + 25%NSC (T2), 25% ECM +50% kocho waste (dupo) + 25% NSC (T3) and 75% kocho waste (dupo) + 25%NSC (T4). The supplement feed offered at the rate of 350 g/day per sheep. The experiment consisted 90 days feeding and 7 days’ digestibility trials followed by evaluation of carcass and meat quality parameters. The CP content of hay, kocho waste, NSC, maize and WB were 8.64, 7.08, 36.9, 8.04 and 17.02%, respectively. Total CP intake was higher (P<0.01) for sheep fed with T1, T2 and T3 than T4 .Apparent OM digestibility and energy intake were higher (P<0.05) for sheep fed with T3 and T4 as compared to those fed T1 and sheep with T2 had similar value to all. CP digestibility for T1 was higher (p<0.01) than T4 while sheep with T2, T3 and T4 were similar. Average daily gain was higher (P<0.01) for sheep fed T3 than T1 and T2 and that for T4 was higher than T1and similar with T2 and T3. Feed conversion efficiency for T3 was highest (P<0.05) than T1 and T2, while no variation among T1, T2 and T4 was observed. Slaughter body and Empty body weight were higher (P<0.01) for T3 than for T1 and T2 while T2 and T4, and T2 and T1 did not differ from each other in these parameters. There was significant difference in Hot carcass and cold carcass among treatments and comparisons follow similar trend with slaughter and empty body weight. Chilling loss of T4 was lower (P<0.001) than all treatments. Rib eye area (REA) was higher (P < 0.01) for T3 and REF thickness of T4 was higher (P< 0.001) than T1, T2 and T3. Basic primal cut of dissected half carcass such as rump, lion and brisket were higher for T3 and hind leg and left carcass for T3 and T4 were significantly higher than that of T1 and T2. Proportion of lean tissue for T3 and T2 was numerically but not statistically higher than T4 and T1. However, fat proportion was higher (p<0.05) for T4 and T3 than T2 and T1 and T1 has lowest value. The meat of sheep fed T4 diet have light color (P<0.01) than those fed T1, T2 and T3. The value of a* b* which measures redness and yellowness was numerically lower for sheep with T3 and T4 than T1and T2. PH (pH45 and pH24) were not significantly varied among treatments. Drip loss of meat for T1 and T2 was significantly higher than T3 and T4. Thawing loss for T4 was lower than that of T1. T4 had lower cooking loss than T1 and T2. Juiciness and flavor of meat were all significantly higher for T4 than T2 and T1, but no significant difference was observed in tenderness, intensity and general acceptance. Sheep fed with T3 and T4 recorded greater net return and marginal rate of return. The results suggested that kocho waste dupo could fully and economically substitute the energy concentrate as used in the present study with appropriate protein supplement for sheep.