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,

This study was executed to investigate the effects of drinking deep sea water treated by reverse osmosis process (RO-DSW) on growth performance, nutrient utilizability, relative weight of lymphoid organs and the concentration of serum immunoglobulin G (IgG) in broiler chickens. A total of 200 one day old broiler chickens (Ross 308) were equally and randomly distributed into 10 ground floor pens (20 chicks per pen, 5 pens per treatment) bedded with rice-husks. The broilers were offered either fresh tap water (Control) or RO-DSW for 28 days (from d 6 to d 33) as the drinking water. The same basal phase 1 diet for first 2 weeks and phase 2 diet for last 2 weeks were offered ad libitum to the birds. The RO-DSW was prepared by diluting 1:20 ratio with deionized water before offering to chickens. The diet for control birds was supplemented with 0.21 % of food-grade salt to satisfy salt need of the birds. Broiler feeding study resulted that there were no differences in amount of water consumption, mortality and FCR between RO-DSW and control chickens. However, feed intake and body weight gain were increased (p<0.05) by RO-DSW drinking. There was no (p>0.05) difference in nutrients utilizability between RO-DSW and fresh water drinking. There were no (p>0.05) differences in the immune response between the control and treatment group. The serum IgG levels were 3.01 vs 2.87 mg/ml and the relative weights of spleen, thymus and bursa of Fabricius were 0.23, 0.18 and 0.20 vs. 0.20, 0.17 and 0.14 for RO-DSW vs. control birds, respectively. The immune responses were tended to be improved by RO-DSW drinking. This study showed an improvement in weight gain and feed intake that could be induced by RO-DSW drinking, although it is difficult to explain the reasons of the improvement at this moment. This study implied that RO-DSW could be successfully used as drinking water to broiler chickens.

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