Table 1.

Comparison of reproductive performance (LS means and range between farms) between 5 organic and 5 conventional Swedish piglet producing herds (n=4697 farrowings; whereof 830 in the organic herds and 3867 in the conventional herds)

Trait	Herd type		p-value
	Organic LS means (Range)	Conventional LS means (Range)
Total number of piglets born per litter	13.6 (12.7-13.8)	12.8 (12.2-13.5)	0.0006
Number of piglets born alive per litter	12.4 (10.8-12.9)	12.0 (11.7-12.6)	0.6
Number of piglets stillborn per litter	1.2 (0.9-2.2)	0.8 (0.5-0.9)	<0.0001
Number of piglets weaned per litter	9.8 (9.0-10.8)	10.0 (9.7-10.4)	0.06
Length of nursing period (=age at weaning) in days	50 (40–58)	34 (33–39)	<0.0001
Farrowing interval in days	178 (169–191)	158 (156–165)	<0.0001