الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c2e504528ec992349130cf9c12987e86Testhttps://doi.org/10.1186/s13567-021-00970-6Test
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::662fbe884b98ac8bdb8ddae30a6eca4dTest