| Based on the theory and methods of Eco-Nutrition, this study was conducted to investigate the effect of body weight and stocking density on growth, feed intake and ecological water parameters of Cynoglossus semilaevis Günther the in industrial culture with Recirculation Aquaculture System; by the experiment of effect of different feeding regime on the growth and water quality, the best feeding assembled mode was found; finally, a new industrial culture feeding mathematical model that can get best growth performance, lowest feed waste and steadily provide motablites to the biological filter was built up.1. The experiment was conducted for 44 day to investigate the effect of six body weight stages(45-550g) and two stocking density levels(normal and high ----added 20-30% on normal level) on growth performance, feed intake and water quality parameters for Cynoglossus semilaevis Günther intensively cultured in recirculation aquaculture system.The results shown that:(1) daily weight gain(DG), daily feed intake and feed conversion ratio (FCR) were positively correlated to body weight, but SGR and daily feeding rate negatively; the comparative concentration of water quality parameters (NH4+-N, NO2--N, COD, PO4-) also negatively; (2) under the condition of general water quality, the high stocking density decreased the growth and intake, meanwhile increased the content of harmful waste in water;(3) the new finding in this study was that daily feeding rate (0.43-0.92%) was significantly lower than the conventional one (2-5%) recommended by previous studies;(4) under conditions of the experiment, the SGR of Cynoglossus semilaevis Günther was 1.42 0.50 %/d, the FCR 0.680.86, the ammonia in water 8.45 1.51mg·kg-1·h-1.2.The second experiment was conducted for 56 days to determine the effects of monthly satiation degrees and distribution ratio of daily feeding ration on growth performance, water quality and immunity activity of juvenile Cynoglossus Semilaevis Günther (with average initial weight 291±4.21g) in the industrial culture condition with closed recirculation seawater. The results indicated that:(1) the monthly satiation degrees significantly effected the growth, feed intake and the ammonia, but did not significantly effect the other water quality parameters, FCR and blood immunity activity ;(2) the DG, SGR, ammonia of 80% satiation degrees was significant lower than the other groups,; the ammonia and daily feed intake of 90% satiation degrees was significant lower than 100%,110% group, meanwhile the daily feed intake and the ammonia of 110% satiation degree were significant greater than the other groups; there was no significant difference on growth performance between 90%,100% and 110% monthly satiation degrees; (3)The SGR and the ammonia of same distribution ratio was significant greater than the difference distribution ratio, the FCR low; immunity activity had no significant difference; (4)according to the experiment result, the 100% satiation degree with same distribution ratio has the highest growth speed; considering the growth and water quality , 90% satiation degree with different distribution ratio was the best feeding regime.3.The feeding mathematical model of Cynoglossus Semilaevis Günther was built through the logarithmic transformation of the data, multiple linear regression.(1)The feeding mathematical model shown as follow: F投: daily feeding ration( g·d-1·fish-1),W: body weight( g·fish-1), D: stocking density(kg/m2), X: satiation degree,T:temperature, T0=21℃,20≤T1≤24℃.(2)The two mathematical models of daily harmful nitrogen and daily gain were founded as follow: UN: total daily harmful nitrogen(g·d-1·fish-1); DG: daily weight gain(g·d-1·fish-1).(3)the use of the model:①the useing of model (1) makes the feeding ration quantitatively, cleanlily and dynamicly.②In the model of (2) and (3), any variable can figure out when the other four variables were known.③Figure out the ecological feeding ration. The original material of total daily harmful nitrogen and DG was both from nutritional component in the feed. The lowest ratio of UN and DG represent that most part of feed was used to growth and the lowest part to waste. So call the feeding ration with the lowest ratio was the ecological feeding ration.④The bulding and complementary of the model can achieve the purpose of getting best growth performance, lowest feed waste and steadily providing motablites to the biological filter, and also brings the feeding technique and water qulity control into mathematical and dynamic level.
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