Biological fermentation of fish waste for potential use in animal and poultry feeds

Biological fermentation of whole fish, viscera and heads using Lactobacillus plantarum was evaluated and the minimum lactose necessary for a successful fermentation under pilot conditions was found to be 5%. Preheating the fish before fermentation decreased the amount of soluble nitrogen substances both before and after fermentation. The relationships between lactic acid bacteria growth, yeast and mold growth and pH indicated that it may be necessary to add an antimycotic agent to achieve and maintain sufficiently low pH values for successful fermentation and storage. Fermentation temperatures of 25 and 35°C and inoculum size of 10³ organisms g⁻¹ of fish produced successful fermentations.