Abstract

This work was carried out to evaluate the effect of different levels (0.0, 0.5, 1, 1.5 and 2 kg per ton) of prebiotics (yeast culture concentrate derived from the outer cell wall ofSaccharomyces cervisiae) on the length trait of the fingerling rainbow trout. This experiment was conducted in split plot with complete randomize design (CRD) amid 500 rainbow trout (each 40 g). The length of fishes was recorded in four biometry periods (each for ten days). The result shows that the prebiotic intake had significant effect on fish length and treatment with 0.5 kg per ton showed better performance than others. Also, the results indicated that the best time for prebiotic intake was in the first biometry period. Generally, the result of this study suggested the use of prebiotic for improved health, production yield and economic profit in aquaculture industry.

Key words: Prebiotic, length, rain bow.