The relative abundance of Enterobacteriaceae is shown in Table 4. A total of 31 enterobacterial sequence reads was detected (17 in the low dietary ZnO experimental group, and 25 in the high dietary ZnO experimental group). According to the Pearson’s χ2 test, the total number of enterobacterial species detected in all piglets of each group was less in the control group than in the high dietary ZnO group (χ2 value: 72.7; P
< 0.001).