Funding for this research was provided by:
Shandong Provincial Modern Agricultural Industry Technology System (SDAIT-21-05)
Shandong Province Science and Technology Development Program (2014GSF121004)
the National Nature Science Foundation of China (31570167)
Shandong Agricultural Science and Technology Innovation Project (CXGC2016B14)
Received: 14 February 2017
Accepted: 3 January 2018
First Online: 19 January 2018
: The animal experiments were approved by the Bioethic Committee of Shandong University (Permit Number: SYXK (Shandong Province) 2014 0011). This study was conducted in strict accordance with the rules of the Bioethic Committee of Shandong University. The farmers participated in this study provided oral informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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