Table 3.

Least square means and SEM for egg-laying traits of Rhode Island Red, White Leghorn, and their reciprocal hybrids.

Trait1	Population2				SEM	P-value3
	RIR	WL	RIR × WL	WL × RIR		$\psi 1$	$\psi 2$	$\psi 3$
AFE (day)	154.76	140.30	140.35	138.35	1.76	<0.0001	<0.0001	0.069
EN32	55.58	66.36	71.51	74.12	2.22	<0.0001	<0.0001	0.058
CS32 (day)	6.97	7.42	10.94	10.65	0.99	<0.0001	0.810	0.769
LP32 (day)	1.50	1.66	1.49	1.53	0.17	0.225	0.646	0.766
EN52	148.79	146.83	168.09	173.54	3.10	<0.0001	0.713	0.126
CS52 (day)	5.52	5.57	7.11	7.82	0.59	<0.0001	0.914	0.113
LP52 (day)	2.10	2.25	1.86	1.84	0.38	0.008	0.490	0.920

¹AFE = age at first egg, EN = egg number, CS = clutch size, LP = length of a pause.

²RIR × WL = offspring of Rhode Island Red sires crossed to White Leghorn dams, and WL × RIR = offspring of White Leghorn sires crossed to Rhode Island Red dams.

³$\psi 1$ (purebreds vs. crossbreds), $\psi 2$(within purebreds), and $\psi 3$(within crossbreds).