Funding for this research was provided by:
National Key Research and Development Program (2016YFD0500106)
China Postdoctoral Science Foundation funded project (2019M652450)
Article History
Received: 10 January 2019
Accepted: 25 July 2019
First Online: 6 August 2019
Ethics approval and consent to participate
: All animal experiments in this study were approved by the Ethics Committee on animals of Shandong Agricultural University (SDAUA-2015-012). The feeding and care of all ducks were according to the approved guidelines.
: Not applicable.
: The authors declare that they have no competing interests.