【作者】 孙国祥；

【导师】 刘鹰；

【作者基本信息】 中国科学院研究生院（海洋研究所） ， 海洋生态学， 2014， 博士

【摘要】 大西洋鲑因具有个体大、肉质好、不饱和脂肪酸含量高等优点已被诸多国家引进养殖。但是，传统的网箱养殖模式因易受自然环境影响、对自然资源(土地和水资源)依赖程度高和对环境影响大而逐渐被循环水养殖替代。在养殖中，饲料是决定养殖效率的主要因素之一，而投喂策略是影响饲料采食量和水环境的主要因素之一。目前关于投喂策略对循环水养殖大西洋鲑鱼及系统的影响未见报道。本研究探讨了饲料及投喂策略对大西洋鲑生长及系统氮磷收支的影响效应，构建了基于投喂和体重的经验生长模型和氮磷排放模型，并通过生产实验对上述模型进行验证，得到以下主要结论：(1)饲料种类和日饱食度显著影响大西洋鲑生长和饲料利用。与限饲投喂(80%饱食投喂量)相比，饱食投喂在促进生长、降低饲料系数和提高胃肠组织消化酶活力等方面均有显著影响，但也同时提高了整体死亡率(+53.74%~+115.26%)。饲料和日饱食度对大西洋鲑关键鱼肉品质指标均具有显著影响。增加投喂可以提高肌肉维生素E含量、肌肉系水力和肌肉pH,但会降低肌肉羟脯氨酸含量。饲料种类和日饱食度虽对粪便的流变特性无显著影响，但提高投喂仍能促进粪便黏度的增加，有利于降低水体小粒径悬浮物含量，提高系统固体物去除率。(2)投喂率、投喂频率和养殖密度三因素对大西洋鲑生长、消化和系统水质具有不同的影响程度。生长方面，三者的影响顺序依次为投喂率>投喂频率>养殖密度，最优组合为1.2%日投喂率、4次/d投喂频率以及10kg/m3养殖密度。消化方面，三者影响顺序为养殖密度>投喂率>投喂频率，最优组合为1.0%日投喂率、2次/d投喂频率和15kg/m3养殖密度。系统氮磷排放方面，三者的影响顺序为养殖密度>投喂率>投喂频率，降低总氨氮和总氮的最优组合是1.0%日投喂率、投3次/d喂频率和10kg/m3养殖密度，减小磷排泄的最优组合是0.8%投喂率、3次/d投喂频率和10kg/m3养殖密度。(3)投喂率和投喂频率组合对降海鲑(smolts)生长、饲料营养利用、鱼体成分及氮磷排放具有显著影响。1.6%日投喂率和4次/d投喂频率组合可以显著提高降海鲑生长、降低饲料系数，同时提高对饲料氮磷的利用，减少系统氮磷排放。因此，在降海鲑的投喂管理中，采用80%-90%日饱食投喂和高投喂频率的组合可以获得较好的生长效率和环境影响。(4)采用投喂负荷表述循环水投喂与水质的内在联系。不同投喂负荷显著影响大西洋鲑生长、饲料利用和整体死亡率。投喂负荷为2.4g/L时大西洋鲑具有较优的生长、饲料利用和存活率。同时，氮磷的沉积率达到最大值(48.21%和33.74%)。在此条件下，系统氮输出比例最小(36.07%)，磷输出比例最大(73.93%)。(5)根据上述实验结果建立工业化循环水养殖大西洋鲑投喂-生长模型和系统氮磷排放模型分别如下：投喂-生长模型：G=-0.023F×lnW+0.224F-0.016lnW+0.682氮排放模型：No=2.10×10-4F+4.94×10-4W1.0117磷排放模型：Po=3.69×10-4F+2.61×10-4W0.7605通过大西洋鲑循环水养殖车间的生产中试进行模型准确性检验，投喂生长模型偏离度为12.68%，氮磷排放模型偏离度分别为17.93%和23.65%，结果表明上述模型具有较好的预测能力。更多还原

【Abstract】 Atlantic salmon have been introduced to many countries for cultivating becauseof the advantages of large individual, good flesh and high contents of unsaturatedfatty acids. However, the traditional cage aquaculture is gradually replaced by therecirculating aquaculture systems (RAS), which is due to its vulnerability to naturalenvironmental impacts, high dependence on natural resources (land and water) andlarge impact on the environment. In aquaculture, feed is the major factor indetermining the efficiency and feeding strategy plays a determinant role in regulatingenvironmental impacts of farming. By now, the impacts of feeding strategies onAtlantic salmon and RAS systems have not been reported. This study was conductedto investigate the effects of feed and feeding strategies on the growth of Atlanticsalmon and nitrogen and phosphorus emission of the system. We also constructedempirical weight-based feeding-growth model and nitrogen and phosphorus emissionmodels. Meanwhile, a workshop experiment was used to verify these models. Themain conclusions were as follows:(1) The feed type and daily satiation degree significantly affected salmon growthand feed utilization. Compared with restricted feeding groups (80%satiation),satiation groups had better growth, lower feed conversion ratio and improvedgastrointestinal digestive enzyme activity, while having higher mortality rate(+53.74%~+115.26%). The two factors had significant impacts on the flesh qualityof Atlantic salmon. Increased feeding could improve vitamin E content, water holdingcapacity and pH of muscle, but also reduce muscle hydroxyproline (HYP) content.Although no significant effect s on rheological properties of feces were found, thefecal viscosity in satiation groups was slightly improved. This helped to reduce theconcentrations of small suspended solids in water and improved solids removal rates.(2) Feeding rate, feeding frequency and stocking density had different effectssequence on the growth, digestion of salmon and water quality. For growth performance, the impact order was feeding rate> feeding frequency> breeding densityand the optimal combination was1.2%feeding rate,4times/d frequency and10kg/m3stocking density. For digestion, the impact order was stocking density> feeding rate>feeding frequency and the optimal combination was1.0%feeding rate,2times/dfeeding frequency and15kg/m3stocking density. For nitrogen and phosphorusemissions, the impact order was stocking density> feeding rate> feeding frequency.The optimal combination for reducing total ammonia nitrogen and total nitrogenexcretions was1.0%feeding rate,3times/d feeding frequency and10kg/m3stockingdensity, while the optimal combination for reducing phosphorus excretion rate was0.8%feeding,3times/d feeding frequency and10kg/m3stocking density.(3) The combinations of feeding rate and feeding frequency combination havesignificant effects on growth, feed utilization, body composition and nitrogen andphosphorus emissions of Atlantic salmon. The1.6%feeding rate and4times/dfeeding frequency combination can significantly improve the salmon growth andreduce feed conversion ratio, while improving utilization of nitrogen and phosphorusand the system emissions for N and P. Therefore, the use of80%-90%satiationfeeding and high feeding frequency combinations can get better growth efficiency andenvironmental impact in feeding management of juvenile salmon.(4) The feed loading was adopted to describe the relationship between feeding andwater quality in RAS. Feed loading had significant effects on growth, feed utilizationand mortality of salmon. When fed a load of2.4g/L, Atlantic salmon had optimumgrowth, feed utilization and survival rate. Meanwhile, the deposition rate of nitrogenand phosphorus were the biggest (48.21%and33.74%). Under these conditions, thesystem output the smallest proportion of nitrogen (36.07%), while the proportion ofphosphorus output was the largest (73.93%).(5) Based on the above results, the growth model and excretion model for N and Pwere as follows:Feeding-growth model: G=-0.023F×lnW+0.224F-0.016lnW+0.682N excretion model: No=2.10×10-4F+4.94×10-4W1.0117P excretion model: Po=3.69×10-4F+2.61×10-4W0.7605The above model accuracy was tested through a designed workshop experiment.The deviation of feeding growth model was12.68%, while nitrogen and phosphorusemission model deviation were17.93%and23.65%. The results showed that themodel had good predictive ability.更多还原