INVESTIGADORES
MARIN raul Hector
congresos y reuniones científicas
Título:
Selection for high plasma corticosterone response to immobilization stress delays puberty in Japanese quail hens.
Autor/es:
CADD, G. G.; MARIN R. H.; SATTERLEE D. G.; JONES, R. B.
Lugar:
Atlanta, Georgia, Estados Unidos
Reunión:
Congreso; International Poultry Scientific Forum.; 2002
Institución organizadora:
Poultry Science Association
Resumen:
Selection of Japanese quail for exaggerated stress responsiveness was accompanied by a number of undesirable changes in other traits. These included increased fearfulness, and decreased sociality, body weight, and cortical bone porosity. The present study assessed the effects of divergent selection on the age at onset of puberty. Hens were examined from each of three quail lines: 12 each from a randomly bred (RB, control) line and from those bred for an exaggerated (high stress, HS) or a reduced (low stress, LS) plasma corticosterone response to immobilization stress. Egg production was monitored from the age at which the first egg was laid by any of the hens (found to be 44 d of age). Hen-day egg production (HDEP) was then calculated on a weekly basis for 10 wk of lay and the onset of puberty was assessed by calculation of the average ages at first egg lay (FIRST) and at 25% egg production (TFIVE). The mean age at FIRST was elevated (P < 0.05) in HS quail compared to controls (51.6 d vs. 49.4 d, respectively). The LS hens showed a FIRST value (50.0 d) intermediate to, and not statistically different from, the RB or the HS hens. TFIVE was also greater (P<0.05) in the HS line than in the RB and LS lines (67.4 d vs. 62.7 d and 60.9 d, respectively). The relative delay in puberty apparent in the HS quail was also reflected in their weekly HDEP means that were lower (P<0.05) than those of both the of other lines in weeks 1 (RB), 2 (RB and LS) and 3 (LS). Given the consistently high level of egg production in the Japanese quail, the absence of group differences in cumulative HDEP values was not unexpected. The present results suggest that the attainment of puberty would be compromised if a selection program included a high stress responsiveness phenotype.
