Scientific Opinion on the safety and efficacy of Optiphos® (6-phytase) as a feed additive for chickens and turkeys for fattening, chickens reared for laying, turkeys reared for breeding, laying hens, other birds for fattening and laying, weaned piglets, pigs for fattening and sows
The additive Optiphos® is a preparation of 6-phytase produced by a genetically modified strain of Pichia pastoris; it is presented in solid (G/CT) and liquid (L) forms ensuring 4000 OTU/g and 8000 OTU/mL, respectively. This product is intended for use in chickens and turkeys for fattening, chickens reared for laying, turkeys reared for breeding, laying hens, other birds for fattening and laying, weaned piglets, pigs for fattening and sows. The final enzyme preparation contains no cultivable production organism or recombinant DNA. All major species tested tolerated the additive at 100-fold the maximum recommended dose. Consequently, the FEEDAP Panel concludes that the additive is safe at the maximum recommended dose for the target species. Based on the absence of treatment-related adverse effects in two in vitro and one in vivo genotoxicity tests and in a subchronic oral toxicity study, it can be concluded that Optiphos® is of no concern regarding consumer safety when used as feed additive in food-producing animals. The additive is not a skin/eye irritant or skin sensitiser. As an enzyme it is assumed that the additive has potential to be a respiratory sensitiser. The active substance of Optiphos® is a protein and as such will be degraded/inactivated during the passage through the digestive tract of animals. Therefore, no risks for the environment are expected and no further environmental risk assessment is required. Based on data on phosphorus utilisation, digestibility and bone mineralisation, the FEEDAP Panel concludes that the following doses are efficacious: (i) 125 OTU/kg in chickens for fattening and reared for laying, laying hens and sows, (ii) 250 OTU/kg in turkeys for fattening and reared for breeding, weaned piglets and pigs for fattening. The data from major poultry species can be extrapolated to other avian species for fattening and laying at a dose of 125 OTU/kg.