Table 1 The bacterial abundance (WBCN, lg copies/mL) in the water pipe and the V-troughs on different tiers in the layer house during summer.

Water pipe

1st

6.54 ± 0.61

6.85 ± 0.47

6.75 ± 0.22

7.98 ± 0.27

7.02 ± 0.41

7.06 ± 0.28

3rd

6.32 ± 0.87

7.06 ± 0.35

6.91 ± 0.26

7.98 ± 0.20

7.02 ± 0.42

6.86 ± 0.13

5th

6.50 ± 0.77

6.86 ± 0.33

7.02 ± 0.17

8.12 ± 0.48

7.52 ± 0.44

7.10 ± 0.37

7th

6.39 ± 0.67

6.76 ± 0.29

7.05 ± 0.29

8.24 ± 0.33

7.61 ± 0.48

7.05 ± 0.31

Mean

6.44 ± 0.73^b

6.89 ± 0.36^b

6.93 ± 0.24^b

8.08 ± 0.32^b

7.29 ± 0.44^b

7.02 ± 0.27^b

V-trough

1st

9.77 ± 0.27

9.58 ± 0.30

9.86 ± 0.25

9.76 ± 0.14

9.75 ± 0.18

9.88 ± 0.31

3rd

9.78 ± 0.22

9.71 ± 0.14

9.66 ± 0.35

9.70 ± 0.41

9.57 ± 0.47

9.84 ± 0.33

5th

9.71 ± 0.24

9.75 ± 0.12

9.76 ± 0.25

9.81 ± 0.24

9.69 ± 0.27

9.72 ± 0.51

7th

9.63 ± 0.31

9.41 ± 0.50

9.85 ± 0.25

9.73 ± 0.25

9.77 ± 0.25

9.79 ± 0.42

Mean

9.72 ± 0.26^a

9.61 ± 0.27^a

9.78 ± 0.27^a

9.75 ± 0.26^a

9.70 ± 0.29^a

9.81 ± 0.39^a

Ratio of the mean WBCN in the pipe water and the mean WBCN in the V-trough water

1,905.46

524.81

707.95

46.77

257.04

616.60