Two experiments were carried out to determine the nutritive value of sorghum, millet, cassava and sweet potato with or without enzyme supplementation in broiler chickens production. The growth performance, nutrient digestibility, heamatological parameters and characteristics of broiler chickens were evaluated. In the experiment 1, diets were not supplemented with enzyme while in the second, the diets were supplemented with Maxigrain enzyme. Five isonitrogenous and isocaloric diets (23.17 % CP; 2831 Kcal/kgME) and (21.73 % CP; 2929 Kcal/kgME) for the broiler starter (0 - 4 weeks) and finisher phases (5-8 weeks) respectively were formulated. Diet T1 maize based diet served as the control while diets T2, T3, T4 and T5 were sorghum, pearl millet, cassava and sweet potatoes based diets, respectively. A total of 225 day- old NAPRI X broiler chicks were randomly allotted to the five treatments. Each treatment consisted of 45 birds with three replicates of fifteen birds each in a completely randomized design. Feeds and water were provided ad libitum. Data collected were analysed using the general linear model procedures of S.A.S. 9.0 and significant difference (P<0.05) in means among the dietary treatments was separated using a tukey test. The result of the first experiment 1 showed that final body weights of 503.44 g and 2302.77 g, feed intake of 819.67 g and 3073.70 g and weight gain of 453.61 g and 1892.07 g were significantly (P<0.05) higher in birds fed the millet based diet (T3) for starter and finisher broiler respectively than the other dietary treatments. The broiler chickens in T3 (millet based diet) recorded significantly (P<0.05) the best feed conversion ratio of 1.62 and the cheapest feed cost per kg weight gain of ^145.90 for finisher phase. Birds fed diet T5 the sweet potatoes based diet gave significantly (P<0.05) poorest values in in FCR, feed cost, weight gain and mortality rate at the starter phase. At the finisher phase, the sweet potato based diet also gave the poorest performance in FCR and feed cost per kg weight gain. The result of carcass showed significant differences (P<0.05) within the treatments in all the parameters measured with the exception of heart and length of intestine. Digestibility trial showed significant (P<0.05) difference in the percent ether extract digestibilities across dietary treatments. Dietary treatments had significant (P<0.05) effect on white and red blood cells. In experiment 2, enzyme with different energy feed sources had significant (P<0.05) effect on all the parameters. Final weight, weight gain, feed conversion ratio, water intake, water:feed ratio and feed cost per kilogramme weight gain with the exception of mortality rate at starter phase. Birds fed the sorghum based diet had the best performance at starter phase with final weight of 627 g, weight gain of 576.85 g and cheapest feed cost/kg gain of ^ 187.95 k. At the finisher phase, sorghum supplemented with enzyme also had the highest final bodyweight, best feed conversion ratio (1.96) and feed cost/kg gain; ^ 171.15 k. The haematological and digestibility results showed significant (P<0.05) differences across dietary treatments. However, based on the results of the studies, dressing percentage was not significantly (P>0.05) difference. It was concluded that millet based diet without enzyme and sorghum based diets with enzyme supplementation can be suitable and effective as an alternative dietary energy source replacement for income in broiler Chicken production.