Abstract:The most constraining factor in goat production in the tropics is underfeeding mainly attributed to limitations of feed both in quantity and quality. This study was conducted to assess the effect of supplementing different levels of air-dried Moringa stenopetala leaf (MSL) as a protein source on nutrient intake and growth performances of Arsi-Bale male goats. A total of 24 yearling goats with average initial body weight of 13.6 ± 0.25 kg were used in the study. The goats were blocked by live weight into four groups (n = 6 per group) and the groups were then randomly allocated into four supplemented treatments. All goats received a basal diet of natural grass hay ad libitum and 340 g/head/day concentrate. The treatments were the control diet with no supplementation (Treatment 1, T1) and diets supplemented with MSL at a rate of 120 g/head/day (Treatment 2, T2), 170 g/head/day (Treatment 3, T3) and 220 g/head/day (Treatment 4, T4). The duration of the experiment was 75 days. The results indicated that the average daily feed intake was (p < 0.001) higher in goats supplemented with T3 and T4 diets. The total dry matter, organic matter, and crude protein intakes of goats fed with T3 and T4 supplementations were (p < 0.001) also higher than those reared in T1 and T2 diets. Goats reared in T3 and T4 diets had lower (p < 0.05) feed conversion ratio than those fed with T1 and T2 diets. The final body weight in goats reared in T3 and T4 diets was 18.2 kg and 18.5 kg, respectively, being (p < 0.05) higher than those of T1 (15.8 kg) and T2 (16.3 kg). The average daily weight gain in goats fed with T3 OPEN ACCESSAgriculture 2015, 5 1184 and T4 diets was 111 and 114 g/goat/day, respectively, which was (p < 0.05) higher than those reared in the control (T1) (54.0 g/goat/day) and T2 (58.1 g/goat/day) diets. It can thus be concluded that goats reared at high level of MSL supplementation (T3 and T4) had better nutrient intake, feed conversion efficiency and growth performances, suggesting its potential as a good protein supplement to natural grass hay at the farmer's management level.