Scientific Opinion on the modification of the terms of the authorisation of AveMix® XG 10 (endo-1,4-beta-xylanase and endo-1,3(4)-beta-glucanase) as a feed additive for chickens for fattening

Following a request from European Commission, the Panel on Additives and Products or Substances used in animal Feed (FEEDAP) was asked to deliver a scientific opinion on the modification of the terms of authorisation of AveMix® XG 10 (endo-1,4-beta-xylanase and endo-1,3(4)-beta-glucanase) as a feed additive for chickens for fattening. The additive AveMix® XG 10 is a preparation of endo-1,4-beta-xylanase (xylanase) and endo-1,3(4)-beta-glucanase (glucanase) produced by two strains of Trichoderma reesei. This product, available in solid and liquid forms, is currently authorised for its use as a feed additive in chickens for fattening. The applicant is now seeking a modification of the terms of the authorisation, by reducing the minimum recommended dose from 4000 XU and 900 BGU/kg to 2000 XU and 450 BGU/Kg complete feed. The safety of this product for chickens for fattening, the consumer, the user and the environment were already assessed by EFSA in 2009. Therefore, the present opinion only concerns the efficacy aspects of the use of the additive. The data provided from three trials in chickens for fattening do not support the reduction of the minimum recommended dose from 4000 XU and 900 BGU/kg feed to 2000 XU and 450 BGU/kg feed because analyses of the feeds showed that the intended doses were considerably exceeded. However, the data showed that the product is efficacious at a lower dose than the one currently authorised. The data indicate, as an approximation, that 3000 XU and 600 BGU/kg feed has the potential to improve growth rate and feed to gain ratio in chickens for fattening.