Abstract

Tesfaye Kebede , Tesfaye Lemma, Estifanos Tadesse and Mieso Guru

The study was conducted for 132 days on forty growing Arsi-Bale male goats of 16.78±0.61kg initial body weight to evaluate the use of fresh sweet potato vines (SPV) and concentrate given as sole or mixtures and also to determine the optimum level of substitution. Browsing goats were supplemented with SPV and concentrate, which was gradually replaced with fresh sweet potato vines at five levels: 0% SPV (T1), 25% SPV (T2), 50% SPV (T3), 75% SPV (T4) and 100% SPV (T5). There were no significant differences between T1, T2 and T3 in average daily gain (ADG) . T1, T2 and T3 had significantly (P<0.05) higher ADG (g) (60.13 ± 0.004, 59.52 ± 0.002 and 56.34 ± 0.003 vs. 33.01 ± 0.003 and 20.83 ± 0.001) than T4 and T5, respectively. T5 had significantly (P<0.05) lower ADG (20.83 ± 0.001 g) than other treatments. There were no significant differences among treatments in carcass traits except in fat thickness (mm) which was highest (P<0.05) for T1 (1.67 ± 0.33) followed by T3 (1.33 ± 0.33), T2 (1.17 ± 0.44), T4 (1.17 ± 0.17) and lowest for T5 (1.23 ± 0.15). In general, there was no significant difference among treatments in primal cut (kg) except for T5 which had lowest (P<0.05) leg, loin and shoulder and neck than T1. Similarly, there were no significant differences among T1, T2 and T3 in muscle, fat and bone tissue. Therefore, from this study it can be concluded that 25 and 50% sweet potato vines substitution for concentrate can be used for growing Arsi-Bale male goats finishing with acceptable weight gain, carcass traits and compositions.