Table 2.

Body, pituitary, ovary and oviduct mass of 7‐week‐old hens photostimulated for 1 or 12 days

Duration	1 day		12 days		ANOVA
Photoperiod	SP	LP	SP	LP	Duration	Day‐length	Inter‐action
Body mass	602 ± 11	607 ± 18	772 ± 18	858 ± 19*	<0.001	0.009	0.018
Pituitary mass (mg)	4.5 ± 0.2	5.1 ± 0.2	5.3 ± 0.2	6.4 ± 0.2	<0.001	<0.001	0.219
Pituitary mass (mg)a	5.0	5.6**	5.0	5.8***	0.428	0.001	0.669
Ovary mass (g)	0.20 ± 0.01	0.25 ± 0.01	0.27 ± 0.01	0.34 ± 0.02	<0.001	<0.001	0.386
Ovary mass (g)a	0.26	0.30**	0.23	0.26*	0.280	0.002	0.624
Oviduct mass (g)b	0.13 ± 0.01	0.15 ± 0.01	0.17 ± 0.01	0.23 ± 0.03	<0.001	<0.001	0.112
Oviduct mass (g)c	0.15	0.17	0.15	0.18**	0.824	0.015	0.568

Data are the observed mean ± SEM and estimated values from analysis using body mass as a covariate.

Significance of differences between the means for SP‐LP contrasts; *P < .05, **P < .01, ***P < .001.

^aEstimated mean from ANOVA using body mass as a covariate.

^bObserved values but ANOVA performed on log‐transformed values.

^cBack‐transformed estimated means from ANOVA using body mass as a covariate.