Effect of a microbial phytase on the growth performance, digestibility and retention in a high plant meal inclusion diet for Atlantic salmon (Salmo salar)

The effect of supplementation of a novel phytase (OptiPhos (R); Huvepharma; 750 OTU) to high plant meal inclusion diets for Atlantic salmon (Salmo salar) was assessed. Diets were prepared without phytase, with phytase and with supplemental inorganic phosphorus (MCP). After 61 days significant increases in growth, FCR and protein efficiency were seen in diets supplemented with phytase and with MCP over the negative control (P < 0.05). Addition of phytase significantly increased digestibility of phytate and phosphorus (P) as well as retention over other diets (P < 0.05). Phytase addition significantly decreased faecal P losses while increasing metabolic loss over the negative control (P < 0.05). Addition of MCP showed significant increases in metabolic P loss (P < 0.05). In conclusion, the addition of phytase (OptiPhos (R); Huvepharma) resulted in performance improvements comparable to inorganic P dosing, while significantly improving the reduction of effluent wastes from plant meal-based diets.