Effect of Varying Levels of Zizyphus (Zizyphus mauritiana) Leaf Meal Inclusion in Concentrate Diet on Performance of Growing Yankasa Ram Lambs Fed Maize Stover Basal Diet

This study investigated the effects of the dietary supplementation of Zizyphus mauritiana leaf meal (ZLM) on the performance of Yankasa lambs. Twenty five lambs aged between 6 and 8 months were randomly divided into five groups of five animals each in a completely randomized design to receive supplementary diets containing 0, 10, 20, 30 and 40% ZLM as replacement for cotton seed cake in concentrate supplement to a maize stover basal diet for a period of 120 days. Inclusion of ZLM in the supplement did not signifi-cantly (P > 0.05) affect nutrient intake. There was a significant (P < 0.05) depression on dry matter (DM), organic matter (OM), neutral detergent fiber (NDF) and acid detergent fiber (ADF) digestibility, with 30 and or 40% increases in the level of ZLM inclusion in the supplementary diet. Feeding ZLM containing diets particularly at 30 and 40% levels significantly (P < 0.05) influenced nitrogen utilization. Fecal nitrogen excretion significantly (P < 0.05) increased with ZLM supplementation. Control (0%) and 10% level of in-clusion had similar and significantly (P < 0.05) lower fecal N loss (14.30 and 14.94 g/d), followed by 20% (15.42 g/d), with T4 and T5 having significantly (P < 0.05) higher fecal N loss (22.04 and 22.89 g/d). Uri-nary N loss was significantly higher (P < 0.05) in lambs offered 0, 10 and 20% ZLM (10.88, 11.98 and 11.02, respectively) diets compared to 30% (10.06) and 40% (9.89) receiving higher levels of ZLM, which were significantly (P < 0.05) lower. Nitrogen retention was highest in control (26.19), followed by 10 and 20% ZLM (24.42 and 24.14), which were similar and higher than 30 and 40% supplementations (17.15 and 15.97, respectively). Nitrogen retention as % of intake was highest (50.98%) in animals fed 0% and was least in 40% ZLM supplementation (32.75%). It was concluded that inclusion of ZLM in concentrate diet at 10-20% inclusion levels gave best result in terms of performance than when the leaf meal is included at higher levels to ram lambs.