한국산 선발 계통, 일본산 양식 계통 그리고 이들 두 계통간 잡종 계통 참돔 치어의 사료 이용 효율

Abstract

Feeding and starvation experiments were conducted to investigate the differences of growth performance, total ammonia nitrogen (TAN) excretion rates and feces production rates among the offspring from selected Korean strain (KK, mean body weight (BW); 21.5±0.1 g), cultured Japanese strain (JJ, mean BW; 17.1±0.1 g) and their intraspecific hybrid (JK, mean BW; 17.1±0.1 g) of red sea bream in order to compare their feed utilization efficiency. Fish were hand-fed commercial diet containing 46.7% protein for 2 weeks, three times daily 09:00, 13:00 and 17:00 hrs. Feeding rate for the fish was 3% body weight per day. Feed conversion ratio and protein efficiency ratio of KK is superior to JJ and JK (P<0.05). After daily feeding, the TAN excretion rates reached peaks of 49.03, 58.75 and 36.26 mg/kg fish/hr for the JJ, JK and KK strain, respectively, during the daytime. The peak TAN excretion rate of the KK strain was significantly lower than that of the JJ and JK strain (P<0.05), but daily TAN excretion rates of the JJ, JK and KK strain were not different (P>0.05). When fish were fed at satiation after 4-day starvation, TAN excretion rates reached the maximum values 4 hours after feeding for the KK strain (31.23 mg/kg fish/hr) and 6 hours after feeding for the JJ (44.19 mg/kg fish/hr) and JK strain (41.70 mg/kg fish/hr). After 3-day fasting, the daily endogenous TAN excretion rates (ETE) for the JJ, JK and KK strain was 286.91, 215.66 and 179.29 mg/kg fish/day, respectively, the value of the KK strain was lower than that of the JJ and JK strain (P<0.05). The total feces production rates of the JJ, JK and KK strain were not different significantly, but the proportion of feces production rates with time series for the JJ, JK and KK strain were different (P<0.05) Overall results, selected strain had higher protein utilization efficiency than non-selected strain and the their intraspecific hybrid strain.