Table 2.

Regression analysis for lag-residual vs. residual for fixed- and random-effect growth models for mixed-sex New Hampshire and Brown Leghorn heritage birds.

Model 1	Model [1]			Model [2]			Model [3]			Model [4]
Parameter	Estimate	SEM	Pr > |t|	Estimate	SEM	Pr > |t|	Estimate	SEM	Pr > |t|	Estimate	SEM	Pr > |t|
Intercept	0.00038	0.0004	0.35	0.0003	0.0004	0.35	0.0005	0.0004	0.19	0.0004	0.003	0.29
Slope	0.97	0.0017	<0.001	0.84	0.0091	<0.001	0.91	0.0058	<0.001	0.71	0.012	<0.001
R-square		0.98			0.72			0.88			0.51

¹Model [1]: Fixed-effects model $BW=Wm\times ex{p}^{-ex{p}^{-b(t-t_{inf})}}$; Model [2]: Mixed-effect model including a random effect (Wm_u) for mature BW (Wm); Model [3]: Mixed-effect model including a random effect (b_u) for rate of maturing (b); Model [4]: Mixed-effects model including random effects (Wm_u and b_u) for both mature BW (Wm) and rate of maturing (b).