A total of 720 slow-growing Korean meat-type (Hanhyop 3) chicken were used to evaluate the effect of stocking densities and dietary protein levels on growth performance, meat quality, bone mineral composition, and serum corticosterone. Three (6.3, 9.5, and 12.6 birds/m 2 ) stocking densities and two dietary protein levels (19% and 18%) were factorially (3×2) arranged for six treatments. Overall body weight gain (BWG) was highest (p<0.001) at the lowest stocking density (6.3 birds/m 2 ). The feed intake (FI) of birds at the highest density (12.6 birds/m 2 ) was lower than that of birds at the other densities, but resulted in better feed/gain (F/G). Among 18% protein groups, the overall FI of birds at 9.5 birds/m 2 was higher than that at the lowest density; therefore, birds at 9.5 birds/m 2 had poorer F/G than birds at the lowest density during days 61∼75.Difference in F/G among densities was only significant (p<0.05) during days 61∼75 but not significant (p>0.05) during days 41∼60. Although there were no significant differences (p>0.05) in BWG and F/G between 19% and 18% dietary protein levels, FI of the 18% protein diet was less (p<0.05) than that of the 19% diet. Although there was no difference (p>0.05) in meat TBARS values, meat color differed (p<0.05) with stocking density and dietary protein levels. There was no effect (p>0.05) of stocking density and dietary protein levels on bone mineral composition. Serum corticosterone concentration increased (p<0.05) with increasing stock density but was not affected (p>0.05) by dietary protein levels. This study indicated that a density of 12.6 birds/m 2 is not recommended for slow-growing chickens. Between 19% and 18% dietary protein levels, 18% would be recommended for the Korean Hanhyop 3 chicken in the finishing stage.(Key words: Korean meat-type(Hanhyop 3) chicken, stocking density, dietary protein levels, performance, meat quality, serum corticosterone) † To whom correspondence should be addressed : sjohh@kangwon.ac.kr , 1995;Buyse et al., 1998;Garner et al., 2002;Mench,

Two diet energy levels (high or low) and two bedding material (rice husk or saw dust) treatments were designed for either male or female slow-growing Korean meat-type chicken (Hanhyop 3) to make totally eight treatments for 11∼75 d feeding trial. Body weight gain (BWG) were influenced by energy levels, sex of bird and bedding material type. There were interaction effect among those three factors. Feed intakes (FI) by male bird during each and overall periods were higher than those by female. Diet energy levels and bedding material affected the FI only during final 56∼75 d period, of which FI of high energy diet was higher in male whereas that of low energy diet was higher in female. Although feed conversion ratio (FCR) was improved by high energy diet, the better FCR has dissipated during 41∼75 d, when the most of overall BWG were achieved. Apparent total tract retention (ATTR) of nutrients were higher in male than those in female birds with exception on fat ATTR. Fat ATTR was improved when fed low energy diet regardless of the sex of birds. Both energy levels and sex of bird influenced the color of breast. Thiobarbituric acid reactive substances (TBARS) value of female thigh was higher than that of male. Levels of moisture and P in female thigh were lower although level of fat in female breast was higher than those in male, respectively. This study showed that diet energy levels for Hanhyop 3 chicken, especially during 41∼75 d, should be differently formulated between male and female bird.