Fig. 1. Results from experiment 1. (A) Food intake, (B) body mass on day 21 (shown
as per cent change relative to values on day 0), and (C) change in testicular
volume on day 21 relative to that on day 0. At the beginning of the
experiment, testes of birds in all groups were minimum in size (approximately
0.33 mm3). Photosensitive birds (N=5-6 per group) were
exposed to a 16 h:8 h L:D photoperiod for 3 weeks and received food ad
libitum or for 8 h or 4 h only. Values are means ± S.E.M. except
in A where food intake bird-1 day-1 refers to value
calculated from a group value, obtained from of a group of birds
(N=5-6) housed within one cage (see Materials and methods). *
indicates a significant difference (P<0.05) from day 0 values
(paired t-test); 
indicates a significant difference compared
to the ad libitum group at day 21.
