Abstract:In this study we aimed to explore the influence of feeding rate on the growth of the Chinese giant salamander Andrias davidianus under certain conditions in industrial aquaculture such as water temperature 18–19℃, pH 8.0 and dissolved oxygen 6.0 mg/L. Chinese giant salamander aged 2, 3, 4 and 5-year-old were fed with fresh dead carp at five different rates, and the corresponding growth rates were recorded during 60 days. We compared a variety of growth traits between different groups including the weight gain, the total length increment, the feed coefficient, the weight gain rate, the specific growth rate and the food conversion rate. Two-year-old Chinese giant salamander with feeding rate 2.0% had a significantly lower feed coefficient but higher weight gain rate and food conversion rate than those fed at 1.7%, 2.3%, 2.6%, and 2.9%. Moreover, its specific growth rate was also higher than that of groups fed at 1.7% and 2.6% (P<0.05). Three-year-old Chinese giant salamander with feeding rate 2.2% had a significantly lower feed coefficient than those fed at 1.9%, 2.5%, 2.8%, but higher weight gain rate and specific growth rate than those fed at 1.6%, 1.9%, 2.5% and 2.8%. Their food conversion rate was significantly higher than those fed at 2.5% and 2.8% (P<0.05). Four-year-old Chinese giant salamander with feeding rate 2.3% had a significantly lower feed coefficient but higher weight gain rate and specific growth rate compared to those fed at 1.7%, 2.0% and 2.9%, and its the food conversion rate were significantly higher than those fed at 1.7% and 2.9% (P<0.05). Five-year-old Chinese giant salamander fed at 2.5% had a significantly lower feed coefficient than those fed at 1.9%, higher weight gain rate and specific growth rate than those fed at 1.9%, 2.2%, 2.8% and 3.1%, and higher food conversion rate than those fed at 2.2%, 2.8% and 3.1% (P<0.05). In order to reduce the feed coefficient and to raise the weight gain rate, specific growth rate and food conversion rate, we recommended that the appropriate feeding rates should be 2.0%, 2.2%, 2.3% and 2.5% for 2, 3, 4 and 5-year-old Chinese giant salamander respectively. The optimal feeding rate appeared to increase along with growing age, which conformed to equation y=0.000212x+2.07 (r2=0.8797).
