Erratum to: Vet Res (2017) 48:41 DOI 10.1186/s13567-017-0445-2
After publication of the article [1], it has been brought to our attention that an acknowledgement has been omitted from the original article. The authors would like to include the following, The authors also thank Prof. En-Min Zhou (Northwest A&F University) and his laboratory for technical support.”