Substitution of concentrate mixture with dried brewery spent grains improved biological and economical performance of 50% Dorper × Menz crossbred sheep.

The study aimed to investigate the potential of dried brewery spent grains (DBG) to substitute concentrate mixture (CM) in a diet of growing 50% Dorper × Menz crossbred ram lamb. Randomized complete block design (RCBD) was used for this study, and experimental animals were stratified into 7 blocks based on their initial body weight and age. Ram lambs from each block were randomly assigned to one of the five treatments. Native pasture hay (NPH) was fed to all experimental animals as a basal diet (ad libtum at 20% refusal) and supplemented with 400 g CM (T 1 ) or 300 g DBG + 100 g CM (T 2 ) or 200 g DBG + 200 g CM (T 3 ) or 100 g DBG + 300 g CM (T 4 ) or 400 g DBG (T 5 ). Natural pasture hay and total dry matter (TDM) intake were not affected (P > 0.05) by the inclusion of DBG in the CM; however, supplement intake was greater (P < 0.0001) for DBG than CM alone-supplemented group. Metabolizable energy intake was decreased (P < 0.0001) as CM was substituted with DBG, whereas apparent digestibility was comparable (P > 0.05) among treatments. The treatments with the substitution of 50%, 75%, and 100% of CM with DBG were superior (P < 0.001) in body weight gain to the 100% CM-supplemented group, and the substitution of 25% CM with DBG had an intermediate growth rate. The partial budget analysis revealed that the substitution of 50% and 100% CM with DBG gave greater net returns of Birr 881.19 and 854.91 per head, respectively. Based on MRR, 200 g CM + 200 g DBG is the best treatment, and using this treatment, a farmer can benefit from ETB 8.94 for every 1 ETB investment. Hence, sole DBG or a mixture of DBG with a CM can be used for supplementation in growing 50% Dorper crossbred ram lambs.