Effects of feeding rates on growth performances of white Sturgeon (Acipenser transmontanus) fries

Four 1-week growth trials were conducted to determine the effects of feeding rates on the growth performances of white sturgeon (Acipenser transmontanus) fries 69 weeks after initiation of feeding. Six feeding rates with four replications were used in each of the four trials, and the feeding rates were 3.08.0, 2.07.0, 1.06.0 and 1.06.0% body weight (BW) per day in 1% increment, respectively. Number of fries per replicate and their initial BW (means +/- SEM) were 60, 45, 30 and 30 and 2.8 +/- 0.1, 4.5 +/- 0.4, 8.5 +/- 0.7 and 10.0 +/- 0.7 g, respectively. The fries were kept at 18-19 degrees C and fed a commercial salmonid feed (488 g kg-1 protein and 123 g kg-1 fat). Mortality was low and unrelated to feeding rates. Final body weights, body weight increases, specific growth rates and feed efficiency were significantly (P < 0.05) affected by the feeding rates. Body moisture and lipid contents were significantly affected by feeding rates except body moisture content in trial II. Body protein contents were not affected by feeding rates except in trial III. Broken-line analysis on specific growth rates indicated that the optimum feeding rates were 6.5 +/- 0.4, 4.8 +/- 0.2, 4.2 +/- 0.1 and 3.8 +/- 0.2% body weight per day, respectively, for white sturgeon fries 69 weeks after initiation of feeding.