Yeasts are a rich source of protein and B-complex vitamins. They have been used successfully as a complementary protein source in fish diet (Liao, 1977). Also, they have been used as a supplement in animals feed to compensate for the amino acid and vitamin deficiencies of cereals, and are recommended as a substitute for soybean oil in diets for fowl (Gohl, 1991). In addition they are considered a cheaper dietary supplement as they are easily produced on an industrial level from a number of carbon-rich substrate by-products (Lee and Kim 2001). Crude protein content in the yeast compared favorably with other conventional protein source (Ballerini and Thonon, 1980).