Safety and efficacy of Feedlyve AXC (endo-1,4-β-xylanase) as a feed additive for chickens for fattening

Feedlyve AXC is a feed additive that is available in liquid and solid formulations and contains endo-1,4-bxylanase which is produced by a strain of Trichoderma longibrachiatum. The tolerance trial submitted did not comply with the requirements of tolerance trials, and therefore, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) could not conclude on the safety of the additive for the target species. The enzyme concentrate gave negative results in a bacterial reverse mutation assay and in an in vitro chromosome aberration assay. Moreover, the substance was negative in an in vivo micronucleus test in the rat bone marrow and the results of the subchronic oral toxicity study showed no adverse effects. However, the correspondence of the test item used and the fermentation product that is currently used to prepare the additive was not established. Therefore, the FEEDAP Panel was not in a position to conclude on the safety for the consumer of the additive. The tests conducted in order to address the safety for the user indicated that the test items were not toxic by inhalation, not irritant to the eyes or skin but showed a dermal sensitisation potential. However, the relationship between the test items and the additive for which re-evaluation is sought were not fully established. The additive is considered as a potential respiratory sensitiser. No risks to the environment are expected. The results of five trials showed that 100 AXC U/kg feed increased the content of apparent metabolisable energy of the diets in one trial, and 80 AXC U/kg feed improved the feed to gain ratio in two other trials. The trials providing evidence of efficacy at 80 AXC U/kg feed showed some limitations, and therefore, the Panel considered that there is not sufficient data to conclude on the efficacy of the additive.