Text and Data Mining valid from 2019-02-19
Received: 5 July 2018
Accepted: 8 February 2019
First Online: 19 February 2019
Ethics approval and consent to participate
: The duck embryos used in this paper was approved by the Animal Ethics Committee of Sichuan Agricultural University (approval No. XF2014–18). And the experiment was performed in according to the experiment operational guideline of Sichuan province, China.
: Not applicable.
: The authors declare that they have no competing interests.
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