Figure 4.

(A), DIO2, (B), DIO3 expression and (C) their ratio in basal hypothalamus. Hens were exposed to either either 1 or 12 days of a long photoperiod (LP) (16:8 hour light/dark cycle) or maintained on a short photoperiod (SP) (8:16 hour light/dark cycle). Open bars represent the samples taken during the light period (4 hours after lights on), whereas the solid bars represent the night samples (4 hours after lights off). Specific comparisons between means are indicated for SP‐LP comparisons, *P < .05; ***P < .001. There were no significant night day effects