Planning of experiment the experiment. Random complete block (Randomized Complete, Block Design RCBD) trial in broiler chickens 2 weeks of 80 into 4 groups 4 repeatedly. It 5 when fully 4 week. So coop counts were 16 from 4 groups 4 repeatedly, the result showed 1 try to supplement the waste yeast มันหมัก in broiler ration level, 10 5 0,, and 15 percent. The study was divided into 2 experiments. Experiment study of fermentation of cassava fuel 1 with Saccharomyces cerevisiae can improve the nutritive value better by nutritional composition of cassava in the minimal protein from 2.8 percent. A 18.08 percent. The fermentation time 30 days. It can be seen that the cassava fermentation protein up 15.28 percent when compared with the normal cassava residue