Table 1 Productive parameters (mean ± SD or proportion [percentage] plus confidence interval [CI]) of V and NV sows

Total born piglets /sow

14.1 ± 3.0^a

13.6 ± 3.6^a

Live born piglets/sow

13.4 ± 3.0^a

12.9 ± 3.7^a

Weaning-to-mate interval (days)

4.6 ± 5.1^a

4.6 ± 5.0^a

Weaning-to-fecundation interval (days)

30.7 ± 7.0^a

30.2 ± 5.3^a

Weaned piglets/sow

12.1 ± 2.7^a

11.8 ± 3.7^a

Abortions

4/180 (2.2%)^a

CI: 0.1–4.4%

2/53 (3.8%)^a

CI: − 1.4–8,9%

Mummies

34/2424 (1.4%)^a

CI: 0.9–1,9%

15/695 (2.2%)^a

CI: 1.1–3.2%

Stillbirth

105/2424 (4.3%)^a

CI: 3.5–5.1%

24/695 (3.5%)^a

CI: 2.1–4.8%

Dead suckling piglets

213/2295 (9.3%)^a

CI: 8.1–10.5%

58/658 (8.8%)^a

CI: 6.6–11.0%

Cross-fostered piglets

127/2079 (6.1%)^a

CI: 5.1–7.1%

53/600 (8.8%)^b

CI: 6.6–11.1%

Piglets birth weight (Kg)

1.64 ± 0.39^a

1.58 ± 0.38^b

Weaned piglet weight (Kg)

6.51 ± 1.48^a

6.37 ± 1.48^b