Table 1 Summary of anti-Ascaris serum antibody prevalence in pigs from thirteen farms in Sichuan, China (cf. Fig. 1)

Chengdu

Farm A (intensive)

9

0 (0.0)

0.09 ± 0.14

− 0.02–0.2

1600–2000

Farm B (intensive)

108

73 (67.6)

0.99 ± 0.76

0.85–1.13

5000–6000

Farm C (intensive)

24

19 (79.2)

0.92 ± 0.81

0.58–1.26

3500–3800

Dazhou

Farm D (intensive)

10

9 (90.0)

1.21 ± 0.47

0.87–1.55

800–1200

Farm E (intensive)

7

1 (14.3)

0.33 ± 0.16

0.18–0.48

1000–2000

Farm F (intensive)

8

8 (100.0)

1.15 ± 0.44

0.78–1.52

3500–4700

Farm G (intensive)

8

8 (100.0)

1.15 ± 0.21

0.98–1.33

1100–1200

Deyang

Farm H (intensive)

47

40 (85.1)

0.83 ± 0.39

0.72–0.94

10,000–11,000

Mianyang

Farm I (intensive)

50

13 (26.0)

0.44 ± 0.72

0.24–0.64

11,000–13,000

Farm J (intensive)

91

56 (61.5)

0.69 ± 0.63

0.56–0.82

10,000–12,000

Ya’an

Farm K (extensive)

54

31 (57.4)

0.91 ± 0.83

0.69–1.13

120–150

Yibing

Farm L (intensive)

50

31 (62.0)

0.70 ± 0.57

0.54–0.86

5000–7000

Suining

Farm M (extensive)

46

22 (47.8)

0.56 ± 0.54

0.40–0.72

200–300

Total

512

311 (60.7)

0.78 ± 0.69

0.72–0.84