title: Effects of photoperiods on the weights of bursa of Fabricius and thymus in Japanese quail.
abstract: Effects of photoperiods on the growth of the bursa of Fabricius and the thymus were investigated in male (1-8 weeks after hatching) and female (5-7 weeks after hatching) Japanese quail. In males from hatching to 4 weeks of age, the bursal growth was not affected by photoperiod. However, the growth pattern was different between long and short days after 4 weeks of age, i.e., the bursal weight under long days (LD 16:8) increased rapidly until 6 weeks of age and regressed thereafter, whereas it continued to increase under short days (LD 8:16), keeping a constant ratio to body weight. The growth of the thymus showed a similar pattern to that of the bursa of Fabricius. The age for the thymus to reach the maximum weight under LD 16:8 was almost the same as that for the bursa. In LD 8:16, thymus weight increased until 6 weeks and thereafter remained constant. In females, bursa of Fabricius and thymus weights decreased from 6 to 7 weeks under LD 16:8, which was coincided well with the rapid oviduct growth, whereas the organ weights increased under short days. Thus, it was clearly shown that the growth pattern of lymphoid organs is affected by photoperiods in both male and female Japanese quail.
mesh_terms: D000818:Animals; D002060:Bursa of Fabricius / Q000254:growth & development; D003370:Coturnix / Q000254:growth & development* / Q000502:physiology; D005260:Female; D008027:Light; D008297:Male; D010053:Ovary / Q000254:growth & development; D010057:Oviducts / Q000254:growth & development; D010507:Periodicity; D011784:Quail / Q000254:growth & development*; D013737:Testis / Q000254:growth & development; D013950:Thymus Gland / Q000254:growth & development