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 efficacy of HOSTAZYM^® X as a feed additive for sows in order to have benefits in piglets. This additive consists of endo-1,4-β-xylanase produced by a non-genetically modified strain of Trichoderma citroviride. The additive is to be used in sows at 1,500 EPU/kg feed. In a previous opinion, the FEEDAP Panel could not conclude on the efficacy of the additive when added to feed for sows in order to have benefits in piglets. The applicant provided new efficacy data to complete the assessment of the efficacy of the additive. Based on the previously assessed data and the newly submitted one, the Panel could not conclude on the efficacy of the additive.