Context. Formulating supplements with Gliricidia sepium leaf meal (GLM) and cassava powder to promote liveweight gain of Ongole bulls. Aims. This study was conducted to evaluate the effect of using GLM as a substitute for copra meal (CM) or soybean hulls (SBH) in a concentrate containing dry cassava powder (DCP) on the average daily gain of Ongole bulls and income over feed cost. Methods. Forty Ongole bulls were allocated in a randomised block design with 10 head per treatment. The control group (R 0 ) was provided the current feeding system (CFS) fed ad libitum, with supplemented treatments consisting of the current feeding system fed ad libitum + 1% liveweight (on approximate DM basis)/day of three different concentrate supplement diets (R 1 , R 2 and R 3 ). R 1 concentrate contained 50% DCP, 25% CM and 25% SBH; R 2 was 50% DCP, 25% GLM and 25% SBH; and R 3 was 50% DCP, 25% CM and 25% GLM. The bulls belonged to cooperative smallholder farmers in the Banaran and Bleberan villages, Playen Subdistrict, Gunungkidul Regency, Yogyakarta, Indonesia. The experiment was performed for 12 weeks from 22 December 2018 to 16 March 2019. Key results. The average weight gain of bulls (kg/head) in the treatments R 0 , R 1 , R 2 and R 3 were 0.31, 0.75, 0.61 and 0.62, respectively. The income over feed cost of supplement treatments R 1 , R 2 and R 3 was double that of the control (R 0 ). Conclusions. It was concluded that GLM can replace the use of SBH and CM in a cassava-based supplement and increase the income of farmers in this district. Implications. Cassava powder can be combined with GLM to form a concentrate that increases the average weight gain of Ongole bulls and income of farmers.