Abstract: A study was conducted to evaluate the nutrient intake, N-utilization and growth performance of growing indigenous goats (Mubende type) fed elephant grass and supplemented with gliricidia leaves alone or in mixtures of leucaena and maize bran. The experimental diets comprised of a basal diet of elephant grass offered alone ad libitum (E); supplemented with either 300g DM/head/day maize bran (EB); 300g DM/head/day gliricidia (EG); a mixture of gliricidia and leucaena in equal proportions of 150g DM/head/day (EGL); and a mixture (100g DM/head/day each) of gliricidia, Leucaena and maize bran (EGLB). Thirty young goats 12-16 weeks old and averaging 12.28+2.1 kg were arranged in a randomized complete block design with five treatments and six animals per treatment. The results indicated strong substitution of elephant grass with the supplements which resulted in significant decreased elephant grass dry matter intake. However, supplementation did not affect (p>0.05) total dry matter intake and digestibility but both tended to be higher for the maize bran supplemented treatment (EB) than in the other supplemented diets. Total DM intake was lowest for the goats supplemented with diets containing leucaena especially where leucaena formed a high proportion in the mixture (EGL). Crude protein intake was significantly (p<0.05) improved by supplementation but there was no significant differences among the supplemented diets. However, CPI tended to be higher with the gliricidia supplemented treatments and was highest where gliricidia was supplemented alone (EG). Legume supplementation improved nitrogen absorbed and retained and was significantly higher than the maize bran supplemented diets but there was no significant differences among the legume supplemented diets. However, the highest N absorbed and N retained was obtained in the gliricidia (EG) and the leucaena-gliricidia-maize bran (EGLB) treatments, respectively. Average daily gain (ADG) was greater in the supplemented diets than the control but there were no significant differences among the supplemented diets. Body weight changes revealed that goats supplemented with a mixture of gliricidia, leucaena and maize bran had higher body weights than other supplemented treatments. The study revealed that the productivity of indeginous goats offered elephant grass containing moderate levels of CP may be limited by inadequate energy intake and the inefficient utilisation of N and this can be enhanced by gliricidia supplementation alone or in mixtures with leucaena and maize bran which will improve nitrogen utilisation in the animal body. It was therefore concluded that tree legumes especially gliricidia which is being promoted for use in the smallholder crop-livestock farming systems and maize bran which is a by-product from the major stable food in Uganda can play an important role in maximising utilisation of grass forages hence improving goat production.