Table 1. Regression coefficients (β) between the number of total piglets born and litter characteristics at birth in sows

	Total number of piglets born (n)
	Milligan et al. [40]1)	Wienjtes et al. [5]2)	Wientjes et al. [17]3)	Han et al. [41]4)
Litter characteristics
Mean birth weight (g)	−46***	−40***	−41***	−37***
CV of birth weight (%)	0.39***	0.76***	0.83***	0.60**
Piglets < 1,000 g (%)	-	2.4***	1.9***	2.0***

Conventional YL sows, 10.7 total born piglets (n = 4,222).
Organic Topigs20 sows, 17.4 total born piglets (n = 1,864).
Conventional Topigs20 and Topigs40 sows, 13.5 total born piglets (n = 2,128).
Conventional DanAvl sows, 19.1 total born piglets (n = 1,065).
p < 0.01,
p < 0.001.
CV, coefficient of variation; YL, Yorkshire Landrace.