Cloacal gland development in Male Japanese quail selected for divergent adrenocortical responsiveness.

MARIN R. H.; SATTERLEE D. G.; LAMBERT, T.; GLEISER, R. M.

Atlanta, Georgia, Estados Unidos

Congreso; International Poultry Scientific Forum.; 2003

Poultry Science Association

              The present study determines whether divergent selection for adrenocortical responsiveness altered sexual development in males of the low stress (LS) and high stress (HS) response lines. Sexual development was assessed by examination of their cloacal gland area (AREA) and volume (CVOL), the proportion of individuals that produced cloacal gland foam (PICF), and the intensity of cloacal gland foam production (CFP) at 4, 5, 6, 8, 10, 14, and 16 wk of age. These intervals comprise ages at which growing, photo stimulated quail would be expected to have: 1) no development and no foam production (pre-pubescent), 2) partial development of cloacal gland with some birds producing cloacal gland foam and 3) full development of the cloacal gland and all birds producing foam (all birds reached puberty). Testis weights were also measured at 6 and 16 wk of age. Mean AREA and CVOL were similar in LS and HS quail at 4 wk of age but these measures were significantly larger (P < 0.05) in LS quail than in HS quail at 6, 8, 12, 14, and 16 wks of age. In addition, significantly more (P < 0.05) LS than HS birds expressed foam at 4 and 6 wks. From 8 wks on, all birds were producing foam. Even though CFP results mimicked those found for AREA and CVOL (i.e. LS quail presenting numerically higher CFP than HS quail), no significant differences were observed between lines. Testis weights were higher in LS than HS quail at both, 6 and 16 wks. The results strongly suggest that selection for reduced adrenocortical responsiveness in Coturnix is associated with an accelerated sexual development in males. The enhanced LS male reproductive development remains evident also at an adult age.