Use of the bacteria Streptococcus faecium and Lactobacillus acidophilus, and the yeast Saccharomyces cerevisiae as growth promoters in Nile tilapia ( Oreochromis niloticus)

Abstract

This study evaluated the effects of three types of probiotics, two bacteria and one yeast on growth performance in Nile tilapia. Three diets were formulated containing the optimum protein level (40%) for tilapia fry: one supplemented at 0.1% with a bacterial mixture containing Streptococcus faecium and Lactobacillus acidophilus; a second supplemented at 0.1% with the yeast Saccharomyces cerevisae; and a third, a control diet without supplements. Two additional diets were formulated to contain 27% protein to serve as a stress factor, and were supplemented at 0.1% with either the bacterial probiotic mix or the yeast. The diets were fed for 9 weeks to tilapia fry stocked in 20-l tanks at two densities: a high density of 20 fry per tank as a stress factor; and a low density of 10 fry per tank. Results indicate that the fry fed with diets with a probiotics supplement exhibited greater growth than those fed with the control diet. Of the four probiotic treatments, the 40% protein diet supplemented with yeast produced the best growth performance and feed efficiency, suggesting that yeast is an appropriate growth-stimulating additive in tilapia cultivation.