Funding for this research was provided by:
National Key R&D Program of China (2017YFC1601206)
National Natural Science Foundation of China (31820103014)
Received: 31 December 2019
Accepted: 27 March 2020
First Online: 8 April 2020
Ethics approval and consent to participate
: This study was approved by the Research Ethics Committee of the East China University of Science and Technology, with the approval number of 2015018 on 3rd January 2015. Permission for collecting fecal specimens was obtained from the managers of the farms. Animals were kept according to the Animal Ethics Procedures and Guidelines of the People’s Republic of China.
: Not applicable.
: The authors declare that they have no competing interests.