Effects of probiotics and spirulina on survival and growth of juvenile common carp (Cyprinus carpio)

A 45-day feeding trial was conducted to investigate the effects of probiotics and spirulina on survival, growth, feed conversion ratio (FCR), protein efficiency ratio (PER), and total heterotrophic microbial count in common carp (Cyprinus carpio). Two probiotic organisms (the bacteria Lactobacillus acidophilus and the yeast Saccharomyces cerevisiae) and a single cell protein (Spirulina maximus) were incorporated into diets at concentrations of 1%, 2%, or 3%. The control diet contained no supplement. Spirulina maximus at 3% produced the best and statistically significant (p < 0.05) survival, growth (3.69 +/- 0.10 g), specific growth rate (1.27 +/- 0.02%/d), FCR (0.71 +/- 0.08), and PER (1.96 +/- 0.03). In general, L. acidophilus produced better growth than S. cerevisiae. The highest FCR (1.93 +/- 0.05) was obtained in the control. The total heterotrophic microbial count was highest in S. cerevisiae treatments, followed by L. acidophilus and S. maximus. The present investigation shows that incorporation of a probiotic or spirulina in diets for common carp results in increased growth rate.