title: Carry-over effects of long and short photoperiods on body fattening and gonadal weight of blackheaded bunting (Emberiza melanocephala).
abstract: A study was made of the carry-over effect of long photoperiods followed by short photoperiods ou the fattening and gonadal response in a photoperiodic migratory species, the Blackheaded Bunting (Emberiza melanocephala). The effect was studied in photosensitive and then in photostimulated birds. Two experiments were performed: experiment I with photosensitive males and experiment II with photosensitive males exposed to 30 long photoperiods. In both of them, five groups were submitted to the following treatments for 30 days: Group S, a short daily photoperiod; Group L, a long daily photoperiod; Group LS, alternating long and short daily photoperiods; Group L 2S, one long with two short daily photoperiods; Group L 3S, one long with three short daily photoperiods. The results showed that the inductive effect of long days or the inhibitory effect of short days was affected by intervening reversed daylengths.
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology*; D000818:Animals; D001717:Birds / Q000033:anatomy & histology / Q000502:physiology*; D008027:Light; D008297:Male; D009929:Organ Size; D010507:Periodicity; D013737:Testis / Q000033:anatomy & histology*; D013997:Time Factors