基于生物能量学原理构建异育银鲫生长、饲料需求和污染排放模型

BIOENERGETICS-BASED MODEL TO DETERMINE GROWTH,FEED REQUIREMENT AND WASTE OUTPUT OF GIBEL CARP(CARASSIUS AURATUS GIBELIO)

为构建鱼类生长、饲料需求和污染排放预测模型,提高鱼类精准投喂管理水平,通过收集大量文献中异育银鲫(Carassius auratus gibelio)生长数据(异育银鲫体重0.25—550 g),运用特定增长率(SGR)、日增长率(DGC)、日均增重(ADG-Linear)、热积温系数(TGC)和校正后的热积温系数(Rev.TGC)等生长模型计算其生长速率,并通过计算实际观测值和预测值最小残差和法选出最适生长模型。结果发现,在用TGC模型计算其生长率时,异育银鲫在其生长周期中含有3个异速生长点,根据该点的位置,可以将异育银鲫的生长周期分为3个阶段:0.25—13.1 g(第一阶段)、13.1—172.8 g(第二阶段)、>172.8 g(第三阶段)。在这3个阶段中调整后的TGC模型比其他模型(SGR、DGC、ADG)可以更好地预测实际养殖中异育银鲫的生长性能。鱼类在不同的生长阶段对饲料的需求量由消化能决定,通过计算鱼体储积能、基础代谢能、热增能以及尿液和鳃的代谢能,可以估算异育银鲫的消化能,从而确定其饲料需求量。经估算,对于体重为0.25—506 g的异育银鲫,每生产1 kg鱼,其消化能需求量约为1.94×104 k J。在模型验证时,以粗蛋白分别为43%、37%、31%的饲料投喂不同生长阶段的异育银鲫,并利用营养物质平衡法估计废物排放量。研究发现,实测值与模型预测值显著相关。模型可以在异育银鲫实际养殖过程中,有效预估某个生长阶段异育银鲫的体重、所需要的饲料量以及氮、磷污染物排放量,有望为异育银鲫差异化上市、节省饲料成本、减少饲料浪费以及养殖场的污染评价提供有效的预判工具。

Fish growth model,feed requirement model and pollution output prediction model play a vital role in themanagement of fish culture operations.This study collected numerous literature data about the growth of gibel carp(weight0.25-550g)to calculate the growth rate using SGR,DGC,TGC and ADG growth models.The least squaresmethod was used to optimize the growth coefficient within each growth stanza and to choose the best growth model.The TGC model showed that gibel carp has3growth stanzas in its life cycle:from first-feeding(0.25g)to13.1g(Stanza1);from13.1to172.8g(Stanza2);and>172.8g(Stanza3).Results indicated that the modified TGC modelproduced a better fit of the growth trajectory of gibel carp than other models(SGR,DGC,ADG)in practical aquacultureoperations.Feed requirement of fish in different growth stages was determined by digestible energy requirement(DEreq)based on the summation of expected energy gain,basal metabolism,heat increment of feeding,and urinary andbranchial excretion.It was estimated that the requirement of digestible energy was about1.94×107kJ,for gibel carpwith a weight of0.25-506g.A nutrient mass balance method was used to estimate waste output when gibel carp atdifferent growth stages were fed with43%,37%,31%crude protein,respectively.Similarities in live body weight,weight gain and FCR between the observed values and predicted values revealed that the proposed model producedhighly reliable estimates of growth performance,feed requirement and waste output for gibel carp farmed.