Safety and efficacy of the enzyme preparation Natuphos® (3-phytase) as a feed additive for ducks

The additive Natuphos® is a preparation of 3-phytase (EC 3.1.3.8) produced by the genetically modified micro-organism Aspergillus niger (CBS 101.672). The European Food Safety Authority (EFSA) has already delivered an opinion on the efficacy and safety of this product for piglets, pigs for fattening, sows, chickens for fattening, laying hens and turkeys for fattening, which included the assessment of the safety for the consumer, the user and the environment, as well as the safety aspects of the genetic modification. The FEEDAP Panel is not aware of any new information that would lead it to revise this former opinion. EFSA has now been requested to deliver an opinion on the safety and efficacy of the product Natuphos® when used as a feed additive for ducks. Although studies for efficacy and tolerance have been performed with the solid formulation, results are considered to apply to both forms of the product. The efficacy of phytase from Natuphos® has been established for chickens for fattening and turkeys for fattening, at the respective doses of 375 and 250 FTU kg-1. As the mode of action of phytase in ducks is the same as in the major species, an extrapolation can be made provided the dose range is similar. In this case, the minimum effective dose in ducks has been derived from two balance trials provided by the applicant. These show a positive effect of supplementation with 300 FTU Natuphos® kg-1 on phosphorus utilisation in ducks for fattening. Therefore, the FEEDAP Panel considers that there is sufficient evidence to support the efficacy of Natuphos® in this minor species at the minimum recommended dose (300 FTU kg-1 complete feed). The study in which ducks tolerated more than a 100-fold overdose of the product demonstrated the safety of Natuphos® for ducks for fattening at the maximum recommended dose.