Safety and efficacy of RONOZYME®WX CT/L (endo‐1,4‐β‐xylanase) as a feed additive for sows for reproduction

zootechnical additive, digestibility enhancers, safety, efficacy, xylanase, sows
First published in the EFSA Journal
12 agosto 2019
3 luglio 2019
Scientific Opinion


Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of RONOZYME® WX CT/L as a feed additive for sows for reproduction. This additive contains endo‐1,4‐β‐xylanase produced by a genetically modified strain of Aspergillus oryzae and it is authorised in the EU as a feed additive for poultry for fattening, weaned piglets and pigs for fattening. The applicant requests the extension of use of the additive to sows for reproduction at 200 FXU/kg feed. The FEEDAP Panel concluded that there are no concerns for consumer safety and no risks for the environment are expected from the use of RONOZYME® WX in sows. The FEEDAP Panel concluded that the additive is not a skin or eye irritant, but it should be considered a respiratory sensitiser, but could not conclude on the skin sensitisation potential of the additive. A tolerance trial in lactating sows and two toxicological studies were made available to support the safety of the target species. Based on the data available, the FEEDAP Panel concluded that the additive is safe for sows for reproduction at the recommended level with a wide margin of safety. Three efficacy studies in lactating sows were evaluated. Sows that received RONOZYME® WX showed improvements on the apparent faecal digestibility of the energy in the three trials. The enzyme activity in feed that showed efficacy ranged from 124 to 287 FXU/kg feed, and the FEEDAP Panel concluded that the additive has the potential to be efficacious as a zootechnical additive in lactating sows at a level of approximately 250 FXU/kg feed. No data has been provided in gestating sows, and consequently, the Panel could not conclude on this physiological stage of the productive cycle.

Cas: 9025-57-4

Panel members at the time of adoption

Giovanna Azimonti, Vasileios Bampidis Maria de Lourdes Bastos, Henrik Christensen, Birgit Dusemund, Maryline Kouba, Mojca Kos Durjava, Marta López‐Alonso, Secundino López Puente, Francesca Marcon, Baltasar Mayo, Alena Pechová, Mariana Petkova, Fernando Ramos, Yolanda Sanz, Roberto Edoardo Villa and Ruud Woutersen.
Panel on Additives and Products or Substances used in Animal Feed
feedap [at]
EFSA Journal 2019;17(8):5790
Question Number
On request from
European Commission