虹鳟传染性造血器官坏死症疫苗的应用研究

正虹鳟种鱼注射IHN免疫灭活疫苗对虹鳟第二代苗种的母源抗体有效,苗种成活率提高了60%左右;为30克左右的虹鳟鱼种注射虹鳟IHN免疫灭活疫苗,虹鳟成鱼生产成活率在90%以上;本试验虹鳟鱼免疫灭活疫苗的免疫有效期为18个月。虹鳟是辽宁省养殖的主要冷水性鱼类,分布在本溪、丹东、葫芦岛、辽阳和鞍山市,近年来病害频发,鱼苗发病时的死亡率可达到90%,成为虹鳟鱼养殖的瓶颈因素之一。辽宁省水产技术推广总站2015年承担了辽     

复方中草药对弧菌感染下虹鳟免疫相关基因表达的影响

为探究复方中草药对虹鳟在病原菌刺激下的抗氧化免疫分子机制,将红枣提取物、山药提取物和黄芪提取物按照1∶1∶1比例混合成复合物,分别按质量分数0、0.3%、0.6%和1.2%的比例添加到虹鳟基础饲料中。饲喂体长7.6～8.9 cm的虹鳟幼鱼56 d后进行副溶血弧菌攻毒试验(5.48×10⁶ cfu/尾),4 d后采集虹鳟中肠,利用半定量PCR和实时荧光定量PCR检测虹鳟中肠抗氧化相关基因(GST、HSP90BB、CAT、GPx1、SOD)的表达情况。试验结果显示,与对照组相比,GPx1基因和HSP90BB基因表达量在0.3%添加组极显著上调(P<0.01),GST基因和CAT基因表达量在0.3%和0.6%添加组均显著上调(P<0.05,P<0.01),而SOD基因表达量在0.3%和0.6%添加组却显著下调(P<0.05)。试验结果表明,投喂复方中草药添加剂(红枣+山药+黄芪)的虹鳟在副溶血弧菌感染下的抗氧化基因的表达受到明显影响,其抗氧化免疫功能受到显著调控。     

壳聚糖硫酸酯提高异育银鲫抗嗜水气单胞菌感染的研究

对异育银鲫连续7 d分别投喂添加壳聚糖硫酸酯0.1%、0.2%和0.4%的配合饲料,然后用嗜水气单胞菌进行攻毒,以检测壳聚糖硫酸酯对病原菌的抗感染能力。实验结果显示,与对照组相比,试验组呈现出不同程度的免疫保护作用,其中以壳聚糖硫酸酯添加量为0.2%试验组的免疫保护效果最明显,异育银鲫的成活率达到46.67%;添加量为0.1%和0.4%试验组的成活率分别为23.33%和30.0%,而攻毒对照组100%死亡。然后将添加0.2%壳聚糖硫酸酯的饲料用同样的方式投喂异育银鲫,检测其血清和肝组织中的酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、溶菌酶(LSZ)和超氧化物歧化酶(SOD)活性,并分析肝组织中各酶的基因表达量。结果显示,异育银鲫血清和肝组织中的ACP、AKP、LSZ和SOD活性均得到显著提高,且四种酶的活性均呈现随时间延长而先升高后降低的趋势,并于第三天达到峰值,血清和肝组织中ACP活性比对照组分别提高了54.62%和26.58%、AKP提高了37.61%和25.88%、LSZ提高了13.42%和35.43%、SOD提高了18.59%和54.62%;试验组异育银鲫肝组织中ACP、AKP和LSZ的mRNA表达量均得到显著提高,并随时间推移呈现出先升高后降低的趋势,于72 h到达峰值,而SOD的mRNA表达量与对照组相比没有显著变化。综合以上结果,壳聚糖硫酸酯能够显著提高异育银鲫非特异性免疫水平,增强抗嗜水气单胞菌的能力,表明壳聚糖硫酸酯可作为免疫增强剂用于鱼类疾病的预防与治疗。     

蝇蛆抗菌肽对鳙鱼生长性能的影响

试验选用体重相近的健康鳙鱼6万尾,分为2个处理组,研究蝇蛆抗菌肽对鳙鱼生长性能及其成活率的影响。对照组的基础日粮中为普通粉料,试验组的基础日粮中添加100mg/kg的抗菌肽。试验期为56d。结果显示:试验期内实验组和对照组饵料系数分别为1.26和1.51,相比对照组,试验组成活率提高了10%,生长速度提高了26%以上,相对增重率分别为(159.86±8.34)%和(185.09±9.71)%,病害发生率降低了30%,饵料系数降低了16.56%。结果表明:蝇蛆抗菌肽可显著提高鳙鱼的生长性能,降低养殖成本,不失为优质的蛋白添加剂。     

金属编码标签对许氏平鲉放流苗种的标记效果

利用金属编码标签(coded wire tag, CWT)对不同规格许氏平鲉(Sebastes schlegelii)放流苗种的不同部位(鳃部鄂弓提肌和背部肌肉)进行了标记实验,从标记苗种成活率、标签保持率、标记后苗种抗氧化酶活性及生长应激相关基因表达等方面评价了CWT的标记效果。结果显示,CWT标记30 d后,不同规格苗种成活率均为100%,小规格苗种鄂弓提肌标记组(SLM组)的实验鱼标签保持率为87%,大规格苗种鄂弓提肌标记组(LLM组)的实验鱼标签保持率为97%,苗种背部肌肉标记的标签保持率均为100%。CWT标记实验鱼特定生长率低于对照组。标记鱼暂养后,SLM组和大规格背部肌肉标记组(LDM)实验鱼肝脏过氧化氢酶(CAT)活性显著高于对照组,所有组实验鱼肝脏超氧化物歧化酶(SOD)活性均显著高于对照组。除SDM组外,其他实验组肝脏中IGF-1 mRNA表达水平显著高于对照组,LDM组肝脏HSP70 mRNA表达水平最低。从存活率与标签保持率的角度考虑,CWT适宜于许氏平鲉苗种的标记放流,但CWT标记的苗种生长慢于对照组,且在免疫相关酶活性和生长及应激基因方面存在显著的表达差异,表明CWT标记操作对许氏平鲉苗种造成了一定的生理胁迫。因此,利用CWT标记的许氏平鲉苗种应有一个相对较长的室内暂养或野性驯化时间,有利于提高标记放流苗种成活率和放流后生长及回捕。     

抗菌肽对黄鳝生长性能及免疫力的影响

在水温27.5℃～31.2℃下，将平均体质量（30±5）g的黄鳝（Monopterus albus）饲养在长2 m×宽2 m的网箱中，分别投喂基础饲料（对照组）和添加抗菌肽200 mg/kg（组Ⅰ）、400 mg/kg（组Ⅱ）、600 mg/kg（组Ⅲ）和800mg/kg（组Ⅳ）的试验饲料。68 d后，测定黄鳝的生长及免疫相关指标及嗜水气单胞菌（Aeromonas hydrophila）攻毒后各组黄鳝的成活率和免疫保护力，研究饲料中添加抗菌肽对黄鳝生长性能及免疫力的影响。结果显示：饲料中添加抗菌肽黄鳝的相对增重率比对照组高8.9%～33.0%，饵料系数降低3.1%～16.2%，成活率高3.1%～7.2%；血清总蛋白（TP）含量显著增加（P<0.05），酸性磷酸酶（ACP）、碱性磷酸酶（AKP）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）、过氧化氢酶（CAT）活性显著提高（P<0.05），添加量为800 mg/kg时AKP活性最大，比对照组增加37.6%。添加量为600 mg/kg时ACP、SOD、GSH-Px和CAT活性最大，分别比对照组增加了63.3%、...     

蝇蛆抗菌肽对日本鳗鲡生长性能的影响

为了研究蝇蛆抗菌肽对日本鳗鲡生长性能及其成活率的影响,本文以日本鳗鲡幼鳗为研究对象,以鳗鲡基础日粮的普通粉料为对照组,对日本鳗鲡幼鳗的成活率、生长速度、相对增重率和饲料系数进行了比较分析。结果显示:试验期内实验组和对照组饲料系数分别为1.24和1.57,相对增重率分别为(193.6±8.74)%和(238.05±9.42)%。相比对照组,试验组成活率提高了9.13%,生长速度提高了22.9%以上,饵料系数降低了21%。试验结果表明:蝇蛆抗菌肽可显著提高日本鳗鲡的生长性能(P<0.05),降低养殖成本,不失为日本鳗鲡饲料的一种优质蛋白添加剂。     

一种佐剂新材料在嗜水气单胞菌灭活疫苗浸泡免疫鲫中的应用效果

为研究蓖麻油聚乙二醇单酯葡萄糖苷(CPMG)在细菌灭活疫苗浸泡免疫中的佐剂作用,将CPMG和嗜水气单胞菌灭活疫苗联合施用,二次浸泡免疫异育银鲫后饲养在室内玻璃缸中,用实时荧光定量PCR(RT-PCR)检测加强免疫后2、4、7、11、14和21 d脾脏中Ig M、IL-1β、C3、C-凝集素和溶菌酶的m RNA表达量,首次免疫30 d后用同源菌株活菌攻击实验鱼;同时,用含CPMG、山莨菪碱复合佐剂的灭活疫苗浸泡免疫异育银鲫一次后饲养在池塘网箱中,定期抽取血液检测血清抗体效价并用同源菌株人工感染实验鱼。结果显示,CPMG佐剂组和无佐剂组的5个免疫相关基因的相对表达量显著高于对照组,CPMG组Ig M基因较无佐剂组更早表达,补体C3、C-凝集素以及溶菌酶的基因表达量更高或表达持续时间更长。血清抗体效价在免疫后2周达到160,6周达到峰值640,12周降低为40。室内玻璃缸中二次免疫30 d后,CPMG组的平均相对保护率达到70.6%,复合佐剂组达到88.2%,均显著高于无佐剂组的56.0%。池塘网箱中一次浸泡免疫30、60和120 d后,平均相对保护率分别为54.6%、44.0%和12.5%。研究表明,CPMG与嗜水气单胞菌灭活疫苗共同浸泡免疫异育银鲫,增强了脾脏中Ig M、IL-1β、C3、C-凝集素以及溶菌酶基因表达,提高了异育银鲫抗嗜水气单胞菌感染的能力。     

光合细菌对团头鲂细菌性败血症的防治

研究了光合细菌(PSB)对团头鲂细菌性败血症的防治效果。试验1设预防组、治疗组1、治疗组2,对照组和空白组,用注射病原菌法感染试验鱼;试验2设PSB处理组和对照组,用浸泡病原菌法感染试验鱼。结果显示:在试验1中,对照组死亡率90%~100%,PSB处理的各试验组为70%~90%;试验2中PSB浸泡组的平均死亡率20%,对照组85%。     

爱德华氏菌灭活疫苗对黄颡鱼免疫相关基因表达及过氧化氢酶、超氧化歧化酶和补体C3活性的影响

为评价爱德华氏菌灭活疫苗对黄颡鱼的免疫效果,分析了灭活爱德华氏菌疫苗对黄颡鱼非特异性免疫应答相关的免疫基因表达和酶活性的影响。结果显示,黄颡鱼鳃组织中抗菌肽基因和肝组织中长型肽聚糖识别蛋白基因在免疫7、14、21、28d后的表达均显著上调,肠道中抗菌肽基因和脾脏组织中长型肽聚糖识别蛋白基因的表达在免疫7、14、21d亦显著上升。血清中过氧化氢酶、超氧化歧化酶和补体C3活性出现不同程度的提高,其中,黄颡鱼过氧化氢酶活力在免疫14、21d后显著高于对照组,超氧化歧化酶活力在免疫14、21、28d后显著高于对照组,在21d达到峰值,补体C3在免疫7、14、21、28d后均显著上升(P0.05),在免疫7d后血清中补体C3的含量达到高峰。试验结果表明,爱德华氏菌灭活疫苗可显著提高黄颡鱼免疫基因抗菌肽和长型肽聚糖识别蛋白的表达以及酶的活性,进一步揭示爱德华氏菌灭活疫苗可提高黄颡鱼的非特异性免疫能力。     

Inter‐specific hybridization between Black Sea trout (Salmo labrax Pallas, 1814) and rainbow trout (Oncorhynchus mykiss Walbaum, 1792)

Thermal shock‐induced triploid and unshocked control hybrids between rainbow trout (Oncorhynchus mykiss) and Black Sea trout (Salmo labrax) and their parental species were produced under hatchery condition by using heat shocks. Triploidization reduced eyed egg rate and alevin yield in all groups. Low survival rate was observed in both shock‐induced triploid hybrid and non‐shock‐induced control hybrids. Although hybrids demonstrated low body weight during the first feeding stage, they reached higher body weight by day 200 when compared with Black Sea trout and rainbow trout. A higher specific growth rate was calculated as 3.60 in the triploid hybrid groups, 1.41 in the triploid Black Sea trout groups and 2.27 in the triploid rainbow trout groups between days 110 and 200. A lower condition factor was determined in the hybrid than in the diploid parental species. A negative value of mid‐parent heterosis (MPH) performance was deected for condition factor, and a favourable MPH was detected for specific growth rate and weight in hybrids.     

Dietary niche expansion and niche shift in native marble trout (Salmo marmoratus) living in sympatry with introduced rainbow trout (Oncorhynchus mykiss)

The non‐native rainbow trout (Oncorhynchus mykiss) has been introduced worldwide for angling purposes and has established self‐reproducing populations in many parts of the world. Introduced rainbow trout often have negative effects on the native salmonid species, ranging from decrease abundance, growth and survival, to their local extinction. Assessing the effects of introduced rainbow trout on the native species is thus crucial to better set up conservation programmes. In this study, we investigated the effects of non‐native rainbow trout on the diet of native marble trout (Salmo marmoratus) living in the Idrijca River (Slovenia). An impassable waterfall separates the stream in two sectors only a few hundred metres apart: a downstream sector (treatment) in which marble trout live in sympatry (MTs) with rainbow trout (RTs) and an upstream sector (control) in which marble trout live in allopatry (MTa). Specifically, we investigated using stable isotopes the effects of rainbow trout on dietary niche, diet composition, body condition, and lipid content of marble trout. We found dietary niche expansion and niche shift in marble trout living in sympatry with rainbow trout. Compared to MTa, MTs had higher piscivory rate and showed higher body condition and prereproduction lipid content. Our results indicate that the presence of rainbow trout did not have negative effects on marble trout diet and condition and that changes in dietary niche of marble trout are likely to be an adaptive response to the presence of rainbow trout, and further research is needed to better understand.     

添加氯化钾和蛋黄对虹鳟精液冷冻保存的效果

为筛选出更有效的虹鳟(Oncorhynchus mykiss)精液冷冻保存液,在以10％ 甲醇和0.3 M葡萄糖作为主要成分的基础上,分别或同时添加0.9 g/L氯化钾和10％ 蛋黄形成四种冷冻保存液,用于虹鳟精液冷冻保存试验,分别形成4个处理组:Ⅰ#(不添加氯化钾和蛋黄)、Ⅱ#(添加氯化钾)、Ⅲ#(添加蛋黄)和Ⅳ#(...     

Are environmental conditions in Finnish streams limiting to early life-history survival in the nonnative rainbow trout?

The nonnative rainbow trout Oncorhynchus mykiss has been an unsuccessful invader in North European streams, although it has been widely introduced. Here we studied whether early life history stages (egg incubation and hatching, first overwintering) act as filters for the establishment of hatchery rainbow trout. Survival of hatched alevins was approximately 80%, whereas only 47% of the embryos survived. However, the latter value was impacted by the high number of unfertilized eggs. Correlation coefficients with embryo survival rate and environmental variables (pH and temperature) were statistically insignificant. In the overwintering experiments, the survival of rainbow trout was 93%. The growth was generally slowed during the winter, but in the spring the growth of rainbow trout exceeded that of the native brown trout. Our data demonstrated that the survival and growth of rainbow trout during early life-history stages were relatively high and comparable to those of the native brown trout. Based on the variables considered in our study, our results suggest that environmental conditions during early life-history stages are not detrimental for rainbow trout in the study streams.     

Maternal variation in juvenile survival and growth of triploid hybrids between female rainbow trout and male brown trout and brook charr

Related sib‐groups of rainbow trout × brown trout and rainbow trout × brook charr triploid hybrids and monospecific diploid and triploid rainbow trout controls were obtained from a common set of rainbow trout dams. On the basis of hybrid juvenile performances, 10 sib‐groups were selected and the corresponding diploid rainbow trouts were raised up to adult stage. Females from each group of rainbow trout were used to produce a second generation of hybrid progeny, the performances of which were analysed for grandmaternal variation and relation with first‐generation relatives. Results showed that hybrid traits (alevin yield and weight, survival and growth of fingerlings) were strongly influenced by maternal origin, and could be correlated to those of rainbow trout controls, but that maternal abilities had a low rate of inheritance. It was concluded that little improvement can be expected through selective breeding within parental populations.     

Phosphorus retention efficiency in rainbow trout fed diets with low fish meal and alternative protein ingredients

ABSTRACT:   Two experiments were conducted to evaluate feed quality and body phosphorus (P) and nitrogen (N) retention by rainbow trout fed test diets with low amounts of fish meal content and alternative low-P protein sources. A fish meal (FM) diet was used as control. Fish weighing 2.0 g and 134.7 g on average were reared with the experimental diets for 30 weeks and 15 weeks, respectively. The experimental diets had a good growth rate and feed utilization. In the first experiment the P retention was higher in the group of fish fed test diets (56 and 69%) compared to the FM-based diet (36%); N retention rates were similar for all groups. In the second experiment, fish were fed the test diet that had the best P retention in the earlier experiment. The P retention was lower than the values obtained in the first experiment (smaller fish), but still higher in the group of fish fed the low FM diet in comparison with the control group (36.0% and 22.2%, respectively). This represents a P loading into the water of 5.9 kg/t and 12.8 kg/t production for the test and the control diet, respectively. Therefore, low-P-loading diets for rainbow trout can be developed through the appropriate combination of alternative protein sources.     

A new potential therapeutic remedy against Aeromonas hydrophila infection in rainbow trout (Oncorhynchus mykiss) using tetra,Cotinus coggygria

Different antibiotic‐based drugs are being used for the treatment of Aeromonas hydrophila infection in rainbow trout, and several studies emphasize the use of medicinal plants as immunostimulants for prophylactic measure against Aeromoniasis disease. However, therapeutic effects of aqueous methanolic extracts of tetra (Cotinus coggygria) against A. hydrophila in rainbow trout were not investigated. Four different concentrations of tetra extract (0 [control], 4, 8 and 12 mg/100 µl) and also two different positive control groups (florfenicol and doxycycline antibiotics) were administered orally using feeding needles to individual rainbow trout, Oncorhynchus mykiss of all experimental groups twice a day after intramuscular inoculation of A. hydrophila. The study period was for 10 days. On 0th, 3rd, 7th and 10th day, blood and tissues were collected from the fish and changes in humoral immune responses, haematology and immune‐related gene expressions were determined. In the study, superoxide radical production was decreased generally in all experimental groups except in 12 mg tetra and florfenicol treatments compared to control (p < .05). Lysozyme activity was generally decreased (p < .05), or no differences were observed in all experimental groups compared to the control. Myeloperoxidase activity was significantly increased in florfenicol‐treated fish group on 7th day (p < .05). Generally, myeloperoxidase activity showed an increase in almost all tetra‐treated groups. Haematological parameters increased but were not significantly high enough in treatments. Almost all immune‐related gene expressions were significantly enhanced on 3rd and 10th day of the study. Survival rate of 53.33% was found in control group. There were no significant differences in survival between control and 4 mg tetra‐treated group (p > .05). All the other groups' survival rate was significantly increased compared to control. The highest survival rate was found in florfenicol group (80%). In 12 mg tetra‐, doxycycline‐ and 8 mg tetra‐treated groups, survival rate was recorded as 74.44%, 70% and 70%, respectively. Our results suggest that tetra methanolic extract is an effective therapeutic remedy against A. hydrophila infection in rainbow trout at the dose of 24 mg/32.34 g body weight/day.     

The growth of rainbow trout (Salmo gairdneri) given diets containing chitin and its relationship to chitinolytic enzymes and chitin digestibility

The growth of rainbow trout fed diets containing 4, 10 and 25% chitin, over a 12-week period, was significantly depressed (P < 0.001) when compared with controls fed diets containing 25% starch. There was no difference in growth rate between control fish and those fed diets containing 10% N-acetyl glucosamine (GlcNAc). Isotopically labelled amino sugars were shown to be oxidized when injected intraperitoneally into rainbow trout. Relatively high levels were found of chitinase activity in the stomachs and of chitobiase in the intestines. These enzyme activities were similar in all the trout, irrespective of the amount of chitin in their diets, except that chitobiase in the intestines of fish fed diets containing GlcNAc showed higher levels of activity than the controls (P < 0.05). Chitin was not significantly digested when fed at 10 and 30% of the diet but the apparent digestibility of pre-cooked starch was 50% when fed at either 15 or 25%, on the basis of the inert indicator (Cr₂O₃) method. Chitinase and chitobiase activities were not reduced in fish fed diets containing 10% chitin and an antibiotic (Tribrissen^®) although the alimentary microflora were completely eliminated. Enzyme activities were not enhanced when live chitinolytic bacteria (Vibrio alginolyticus) were incorporated into diets with 10% chitin; these bacteria were only recovered from the intestine. The evidence indicates an endogenous origin of chitinolytic enzymes in the trout gastro-intestinal tract. The presence of either antibiotic or bacteria in the diet had no effect on the digestibility of chitin.     

Effect of dietary kefir on the growth performance,feed utilization and fatty acid profile of juvenile rainbow trout,Oncorhynchus mykiss

A study was conducted to determine the effect of feeding with diets containing kefir on growth performance and fatty acid profile of rainbow trout (Oncorhynchus mykiss). Four isonitrogenous (450 g protein kg^?1) and isocaloric (4325 kcal kg^?1) diets were prepared in trout feed to contain 0 (control), 20, 50 and 100 g kg^?1 kefir. Fish, initial weight of 46 g, were randomly distributed into triplicate 520‐L fibreglass tanks in freshwater flow‐through system. Fish were fed at 4% of the body weight thrice a day for 12 weeks. The results indicated that survival rate ranged from 97.14 to 100% without significant difference among treatments (p > .05). Whole‐body moisture and lipid composition were significantly affected by diets containing different levels of kefir (p < .05), but no differences were determined in protein and ash. Furthermore, the fatty acid profile of flesh showed differences among the groups. The percentages of saturated fatty acid in the flesh lipid decreased, while 18:3n‐3 and polyunsaturated fatty acids were increased at higher substitution levels of kefir grain. The present study showed that up to 100 g kg^?1 supplementation of kefir in diets could be improve the fatty acid profile, especially PUFA, in fish flesh without adverse effect on the growth, feed utilization and survival rate of rainbow trout.     

Evaluation of 100% Fish Meal Substitution with Chicken Concentrate,Protein Poultry By‐Product Blend,and Chicken and Egg Concentrate on Growth and Disease Resistance of Juvenile Rainbow Trout,Oncorhynchus mykiss

The ability of poultry products to replace fish meal in diets for rainbow trout, Oncorhynchus mykiss, depends on their nutrient composition, cost, and consistency. The aim of this study was to assess the ability of three commercially available poultry products (chicken concentrate, CC, poultry by‐product blend, PBB; or chicken and egg concentrate, CE) to maintain growth and disease resistance when substituted for fish meal in a rainbow trout starter diet. A control diet was formulated to contain 48% crude protein and 18% crude lipid; 100% of the fish meal in test diets was replaced with CC, PBB, or CE. At stocking, fry were counted into groups (50 fish/tank) with six replicate tanks for each diet and fed their respective diets four times daily for 8 wk. All the poultry‐based diets supported growth (over 1600% increase over initial weight), nutrient retention, and feed conversion ratios of rainbow trout fry equal to or greater than those observed for fry fed with the fish meal‐based diet. No effect of diet on survival was observed following subcutaneous injection challenge with Flavobacterium psychrophilum. These data suggest that the examined products can be used in place of fish meal for rainbow trout fry without lowering growth and disease resistance.