TABLE 1.

The estimated heritability of birth weight for Yorkshire and Landrace with different sources of information.

Population	Information	Number of pigs	Number of pigs	${\sigma }_a^2$	${\sigma }_p^2$	${\sigma }_e^2$	h2
	sources	in pedigree	with BW records
Yorkshire	Pedigree	14,226	10,267	0.011 (0.002)	0.013 (0.001)	0.043 (0.001)	0.162 (0.026)
Landrace		12,313	8,919	0.011 (0.002)	0.017 (0.001)	0.056 (0.002)	0.131 (0.025)
Yorkshire & Landrace	SNPs	–	668	0.007 (0.005)	0.024 (0.005)	0.042 (0.005)	0.094 (0.065)

${\sigma }_a^2$, ${\sigma }_p^2$, and ${\sigma }_e^2$ are the additive genetic variance, material genetic variance and residual variance, respectively; standard errors are in parentheses.