Excessive use of phosphate in the aquatic environment is well documented to cause serious eutrophication in water courses. Plant ingredients contain a significant quantity of Phytate Phosphorus (PP) ~65-70% that is poorly utilised in fish species and is a known anti-nutritional factor. As tilapia feed formulations are typically derived from 90-95% plant material there is a significant opportunity to utilise this PP. In terrestrial monogastric nutrition phytase enzyme unlocks considerable (PP) and significantly enhances animal performance. A 93 day feeding trial was conducted to test the performance of a phytase enzyme applied post pellet to an extruded tilapia feed (1500FTU/kg). A 50% reduction in inorganic P supplementation which is a finite and expensive material, was tested to assess the impact of growth performance indices when using phytase to unlock the (PP) that is currently poorly utilised within fish.
Three experimental diets were produced:
Each diet was randomly assigned to quintuplicate groups, (30 fish tank, N=150 in 350l round tanks) Fish were raised in a recirculating system and maintained at a water temperature of 27.7 ± 0.04°C. After 93 days of feeding it was demonstrated that it is possible to successfully replace at least 50% Mono Calcium Phosphate (MCP) with a phytase enzyme and have significantly positive effects on fish performance as detailed in table 2 below.