Cloacal gland growth differences in high and low plasma corticosterone stress response line male quail reared under short daylengths.

D. G., SATTERLEE; TONG, M.; S A, CASTILLE; RAUL HECTOR MARIN

Poultry Science

Poultry Science Association

Año: 2007 vol. 86 p. 1213 - 1217

0032-5791

ABSTRACT Mail quail selected (generation, G32) for reduced (low stress, LS) orMail quail selected (generation, G32) for reduced (low stress, LS) or exaggerated (high stress, HS) plasma corticosterone (B) stress response to briefexaggerated (high stress, HS) plasma corticosterone (B) stress response to brief  mechanical restraint (5 min of immobilization) were studied for differences in the growthmechanical restraint (5 min of immobilization) were studied for differences in the growth of their cloacal glands when reared essentially lifelong on short day (SD) lengths of 8 L:of their cloacal glands when reared essentially lifelong on short day (SD) lengths of 8 L: 16 D. Post-brooding, at 4 wk of age, 96 quail (48 LS + 48 HS) were housed in cages (one16 D. Post-brooding, at 4 wk of age, 96 quail (48 LS + 48 HS) were housed in cages (one LS and one HS male/cage) and the SD light treatment was instigated. Using a digitalLS and one HS male/cage) and the SD light treatment was instigated. Using a digital caliper, cloacal gland (CG) size measurements (length and width, mm) were madecaliper, cloacal gland (CG) size measurements (length and width, mm) were made biweekly beginning at 42 d of age and ending at 196 d of age (28 wk old). CG volumebiweekly beginning at 42 d of age and ending at 196 d of age (28 wk old). CG volume (CVOL) was calculated from these measurements using a literature proposed formula.(CVOL) was calculated from these measurements using a literature proposed formula.  CVOL in both lines increased similarly with increasing age from 6 to 12 wk of age.CVOL in both lines increased similarly with increasing age from 6 to 12 wk of age.  However, beginning at 14 wk of age and thereafter, LS males showed greater (P < 0.05)However, beginning at 14 wk of age and thereafter, LS males showed greater (P < 0.05)  CVOLs than HS ones. No further increases in CVOL were observed in either line at 24 wkCVOLs than HS ones. No further increases in CVOL were observed in either line at 24 wk  of age beyond that seen at 22 wk. This study demonstrated that while both lines show CGof age beyond that seen at 22 wk. This study demonstrated that while both lines show CG  development under short days, eventually, CG growth becomes comparatively stymied indevelopment under short days, eventually, CG growth becomes comparatively stymied in  the HS males. Furthermore, the maintenance of similarly lower CVOLs in HS than LSthe HS males. Furthermore, the maintenance of similarly lower CVOLs in HS than LS  males, CVOLs that showed no further increase from 22 to 24 wk of age, suggests thatmales, CVOLs that showed no further increase from 22 to 24 wk of age, suggests that  holding these quail lifelong on SDs results in, comparatively, yet another permanentholding these quail lifelong on SDs results in, comparatively, yet another permanent  negative reproductive consequence in quail selected for exaggerated plasma B stressnegative reproductive consequence in quail selected for exaggerated plasma B stress  responsiveness.responsiveness.