Abstract:
An experiment was conducted to evaluate feed intake, digestibility, body weight gain and carcass characteristics of Arsi Bale sheep fed a basal diet of wheat straw (WS) supplemented with crushed maize (CM) grain only or with graded levels of dried green Vernonia amygdalina (VA) leaves. Twenty male Arsi Bale sheep with mean initial live weight of 19.36±0.82 kg (mean ± SD) were grouped into five blocks based on initial body weight and randomly assigned to one of the four treatments (WS ad libitum supplemented with 125 g CM grain only (T1); WS ad libitum supplemented with 125 CM and 125g VA (T2), WS ad libitum supplemented with 125 CM and 250 VA (T3), WS ad libitum supplemented with 125 CM and 375 VA (T4)). Water and block salt were available to the animals at all time. The experiment had 90 days feeding trial followed by 7 days digestibility trial after 15 and 3 days of acclimatization period, respectively. The crude protein (CP) content of WS, CM and VA leaves were 3.22, 6.84 and 22.3, respectively. Higher (P<0.001) total DM intake was noted for sheep that consumed T3 (701±8.85 g/day) and T4 (798.8 ±8.85g/day) diets compared to T1 (417±8.85 g/day) and T2 (575.4±8.85 g/day). Crude protein intake is in the same trend as DM intake. Apparent DM digestibility was higher in T3 (70±0.88) and T4 (71.2±0.88) than T2 (64.7±0.88) and T1(57.7±0.88). Similarly CP digestibility was also higher in T3 (81.8±3.52) and T4 (88.1±3.52) than T2 (76±3.52) and T1 (43.7±3.52). Average daily gain was 14, 30.6, 61.3 and 72.2 g/day (SEM=9.71) for T1, T2, T3 and T4, respectively, which was significantly higher (P<0.001) for T3 and T4 compared to T1 and T2. Furthermore, T2, T3 and T4 animals displayed higher (P<0.001) feed conversion efficiency, dressing percentages (P<0.001), hot carcass weight (P<0.001) and rib eye muscle area (P<0.001) than T1. In general, T2, T3 and T4 attained 2.2, 4.4 and 5.16 times higher daily gain than T1, respectively and T2, T3 and T4 produced about 1.5, 3.6 and 4.3 Kg heavier carcasses than T1, respectively. The result revealed that supplementation of VA leaves together with low level of energy source diet such as maize in the present study could be one option to improve nutrient utilization, growth and carcass yield in sheep fed poor basal diet.
