Funding for this research was provided by:
National Natural Science Foundation of China (31672449, 31101738)
National Scientific Program (2011CB302705)
China Agricultural Research System (CARS-37)
Received: 11 May 2017
Accepted: 15 March 2018
First Online: 20 March 2018
: The authors declare that they have no competing interests.
: The protocol was approved by the China Agricultural University Animal Welfare and Ethical Committee (Permit No. DK1406). Experiments were performed in accordance with the Regulations for the Administration of Affairs Concerning Experimental Animals (The State Science and Technology Commission of P. R. China, 1988).
: Not applicable.
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