As about 60% of the total cost of poultry production incurs on feed, therefore, it is the major component, which mostly affects the economical poultry production. Unfortunately the poultry industry of Pakistan is mainly affected by substandard poultry feeding, which is due to limited availability of quality feed resources particularly protein sources. The incorporation of various non- conventional vegetable protein sources in poultry feed, if properly added have given satisfactory results.

Keeping in view a study was conducted to determine the nutritional value of Brewer's dried yeast replacing sesame meal on growth rate and feed utilization of broiler chicks.
Two hundreds and ten day old broiler chicks were randomly divided into seven groups of 30 birds each so as to have three replicate per group, each having ten chicks. The chicks were fed on seven different experimental rations A to G containing Brewer's dried yeast at 0, 5, 10, 15, 20, 25 and 30% of the ration respectively replacing sesame meal.

The results indicated that average weight gain of the chicks fed experimental ration A to G was 1203, 1175, 1175, 1166, 1138, 1127 and 1096 grams respectively. There was a proportionate depression in weight gain as the level of Brewer's dried yeast was increased. The proportionate depression in weight gain with increasing level of Brewer's dried yeast replacing sesame meal could be attributed to poor quality amino acid profile or biological value of the yeast as compared with sesame meal. It could also be attributed to certain anti-nutritional factors or high amounts of nucleic acids of yeast. The feed consumption of the chicks fed experimental ration A to G was 2516, 2484, 2526, 2502, 2436, 2501 and 2469 grams respectively. The chicks fed ration C consumed greater amount of feed, while the chicks fed ration E had the poor feed consumption. The feed consumption showed no proper pattern as was observed in case of weight gain and there was non-significant difference in feed consumption of different groups of chicks The feed conversion ratio of the chicks fed experimental rations A to C was 2.06, 2.11, 2.15, 2.15, 2.14, 2.15 and 2.15 respectively. The results indicated that the chicks fed ration A had the best feed conversion ratio of 2.06 and the feed conversion ratio was adversely affected on account of incorporation of Brewer's dried yeast. The dressed weight of the chicks fed ration A to 0 was 612, 600, 599, 593, 577, 577 and 555 grams respectively. The dressed weight showed the same trend as was observed in weight gain. The dressing percentage was 50.9, 50.1, 50.4, 51.30, 50.80, 51.20 and 50.60 percent respectively and there was hon-significant difference among difference groups. Similarly the weight of internal organs of the chicks per 100 grams of dressed weight i.e. Liver, Spleen, Pancreas, Heart and Gizzard showed non-significant difference among different groups. The economics of incorporation of Brewer's dried yeast revealed that the replacement of sesame meal with Brewer's dried yeast was economically viable.