책임운영기관 농촌진흥청 국립축산과학원

The aim of this study was to identify the feather section among the whole feather, rachis, 24 and vane with the highest reliability for corticosterone measurement in 10 Pekin ducks aged 42 days. 25 In total, 60 samples (i.e., 20 per section) were collected and each section was analyzed in duplicate. 26 Corticosterone levels were measured using ELISA and statistical analyses were performed using 27 ANOVA in SAS 9.2, and the intra-class correlation coefficient (ICC) was tested using IBM SPSS. The 28 levels in the whole feather (12.55 ± 4.41 pg/mg) was significantly lower (p <.001) than that in the 29 rachis (18.12 ± 5.70 pg/mg). No significant differences were observed between the rachis and vanes 30 (20.40 ± 3.04 pg/mg). ANOVA results confirmed substantial hormonal variability depending on the 31 feather part analyzed. The ICC for the whole feather, rachis, and vane were 0.923, 0.876, and 0.004, 32 respectively. The vane section exhibited the highest concentration and lowest variance, whereas the 33 whole feather exhibited the highest ICC. Although the whole feather had the lowest concentration, 34 it exhibited greater consistency. Further research is necessary to improve the feather corticosterone 35 analysis method for more accurate analysis. In conclusion, the whole feather provides the most re- 36 liable measure of corticosterone concentration among the three parts.