This study used largemouth bass (initial average weight: 33.33 ± 1.8 g) to explore the effects of adding different brown algae extracts to feed on the fish’s growth, immunity and intestinal health. Six groups were set up: a control (Group A), 0.1% sodium alginate (Group B), 0.1% oligotriosaccharide I (Group C), 0.1% oligotriosaccharide II (Group D), 0.2% brown algae powder (Group E) and 0.2% brown algae powder enzymatic product (Group F), with three replicates of 35 fish each, and a 56-day feeding experiment. Results: Compared to Group A, Groups C, D and F had a higher specific growth rate and lower feed coefficient (p < 0.05). Group D had enhanced serum SOD activity; Group F had increased antioxidant enzyme activity and decreased MDA content (p < 0.05). All experimental groups had higher serum LZM levels (p < 0.05), with no IgM difference (p > 0.05). In the intestine, treatment groups had higher α-amylase activity (p < 0.05) and no lipase difference (p > 0.05), and Groups C, D and F had higher trypsin activity (p < 0.05). Group F had the tallest villi, Group B had the thickest muscular layer (p < 0.05), and villus width was similar among groups (p > 0.05). The experimental groups had fewer intestinal pathogenic bacteria, and Group F had improved intestinal microorganism diversity and richness (p < 0.05). In conclusion, adding 0.1% oligotriosaccharide and 0.2% brown algae powder enzymatic product to feed can promote largemouth bass growth, antioxidant capacity and immunity. The 0.2% brown algae powder enzymatic product is better for intestinal development and flora improvement.

The homeostasis of the intestinal microbiota of fish is beneficial to fish health, while food can affect the intestinal microbiota. Tilapia (Oreochromis spp.) has great economic value and is a good model to use in studying the digestion and absorption of nutrients. Furthermore, at present, due to a high demand and high price of high-quality feed raw materials, the nutritional composition of aquafeeds has been changing dynamically. There has yet to be a comprehensive review of research conducted on the influences of dietary macronutrients (proteins, lipids, and carbohydrates) on the tilapia intestinal microbiota. Therefore, this review focuses on the effects of dietary macronutrients on the gut microbiota of tilapia. Interestingly, we found that the best growth performance might not represent the best composition or functions of the gut microbiota. Overall, the unscientific addition of macronutrients to feed is harmful to the intestinal microbiota. Therefore, both growth performance and gut microbiota should be considered when evaluating certain macronutrients. It is our hope that this review will aid in regulating the intestinal microbiota of fish through nutritional means, thereby promoting tilapia farming.

探究不同鲢鳙配比对多品种鱼类混养池塘水体浮游动物群落结构和养殖效能的影响,筛选出基于优良水质和产量的多品种混养的鲢鳙配比,为其规模化生态化养殖提供科学参考.设置鲢鳙配比为1∶1(A组)、3∶7(B组)和1∶9(C组)3个试验组,每组同时配养相同密度的青鱼(Mylopharyngodon piceus)、鲫鱼(Caras-sius auratus)、鲤鱼(Cyprinus carpio)、鲮鱼(Cirrhinus molitorella)和胡子鲇(Clarias fuscus),进行为期194 d的养殖试验,期间共进行7次浮游动物样本采集和2次生长指标测定,分析各组浮游动物的群落结构和养殖效能指标.结果发现,A、B、C 3组试验组共鉴定出浮游动物4类30种,其中轮虫种类最多,均占55%以上;B组的浮游动物种数最多,比A、C组分别高8.00%、3.85%;各组浮游动物密度为57-253 ind./L,生物量为0.32-8.22 mg/L.浮游动物Shannon-Wiener多样性指数(H)、Margalef丰富度指数(D)及Pielou均匀度指数(J)均为B组最高,分别为2.14、0.97和0.87,且β-中污染和重污染次数最少,表明B组水质优于A组和C组.鲢鱼(Hypophthalmichthys molitrix)的增重率、特定生长率和肥满度均为B组最大,其增重率和特定生长率较C组显著提升,分别提高24.92%和3.81%;鳙鱼(Aristichthys nobilis)的增重率、特定生长率和肥满度均为A组最大,其增重率和特定生长率较C组显著提升,分别提高18.43%和3.50%,但与B组无显著差异.B组池塘试验鱼平均增重率、存活率和单位面积产量最高,分别为16824.53%、93.90%和1.42 kg/m2,较C组显著提升,分别提高12.49%、1.90%和19.33%;B组饲料系数(1.04)最低,较C组(1.30)降低20%,两组间差异显著.总体上,"3∶7"的鲢鳙配比有利于多品种鱼类混养池塘水体生态健康,能够提高浮游动物群落多样性,降低饲料能耗并增加养殖效能.

To identify the optimal stocking rate of Micropterus salmoides culture in a land-based round pond recirculating aquaculture system, five stocking densities were tested, i.e., D1–D5 with 60, 70, 80, 90, and 100 fish/m2, respectively. The water temperature of the experimental pond was 20.0–26.5°C. The effects of stocking density on culture productivity and physiological indexes of M. salmoides (initial body weight 50.83 ± 7.28 g) were examined. The D1 and D5 treatments exhibited significantly improved growth performance. The population weight gain in the D5 treatment was the highest, which increased by 63.73%, 52.82%, 60.93%, and 45.08%, compared with groups D1–D4 ( P < 0.05 , each), and the feed conversion ratio was the lowest, which was decreased by 5.65%, 12.03%, 26.42%, and 21.48% compared with groups D1–D4. The levels of crude protein, essential amino acids, and total free amino acids in muscle tissue of group D3 were higher than those in the other groups. Stocking density did not differ significantly on muscle fatty acid composition P > 0.05 , each). The activities of serum AKP and LZM and liver SOD, AKP, and LZM in group D5 were significantly higher than those in the other groups. Thus, 100 fish/m2 was the optimal stocking density of M. salmoides at a size stage of 50.83∼130.13 g in the circulating water of land-based round ponds.

设置 4 个试验组(A、B、C、D)和 1 个对照组(E),在不同的试验条件下,对巴马拟缨鱼进行人工催产,采用双抗体夹心法,测定样本鱼催产前后血清激素水平,试验周期 365 d.结果表明,催产前,C组的雌二醇(E2)含量最高,较A组有显著提高(P＜0.05),与其他各组无显著差异(P＞0.05);D组的雌三醇(E3)和睾酮(T)含量最高,各组间无显著差异(P＞0.05);A组的孕酮(P)含量最高,组间差异不显著(P＞0.05);B组雌酮(E1)含量最高,较A组和D组有显著提高(P＜0.05),与C组无显著差异(P＞0.05).催产后,A组E2 含量上升,B、C、D组下降,且C组催产前后差异显著(P＜0.05);A、B组E3 含量均上升,其中B组催产前后差异显著(P＜0.05),C、D组下降,催产前后差异不显著;A、B组P含量下降,而C、D组上升,催产前后差异不显著(P＞0.05);A、B组E1 含量下降,A组催产前后差异显著(P＜0.05),B组催产前后无显著差异(P＞0.05),C、D组上升,催产前后差异显著(P＜0.05).指出,B、C和D组有助于提高巴马拟缨鱼E1、E2、E3 和P水平,进而促进人工培育条件下的性腺发育,对催产激素有较高的敏感性,是培育巴马拟缨鱼亲本的可选模式.

为研究陆基圆池循环水养殖条件下大口黑鲈(Micropterus salmoides)适宜的养殖密度,设置55、65、75、85、95尾/m2等5种养殖密度(分别标记为A1、A2、A3、A4、A5组),进行了63 d的大口黑鲈养殖试验,通过测定和分析试验鱼的体质量日增长率、体长日增长率、饲料系数、体质量均匀度和单位面积产量等指标,评价不同养殖密度对大口黑鲈生长和主要养殖效能的影响.结果显示:(1)从次低密度的A2组(65尾/m2)至密度最高的A5组(95尾/m2),试验鱼的体长日增长率基本上随着养殖密度的提高而下降,最高的A2组比A3、A4和A5组分别高了31.6％、82.9％和92.3％,并且差异显著(P<0.05);(2)从A2组至A5组,试验鱼的体质量日增长率和特定生长率均随着养殖密度的提高而下降;(3)A2组的饲料系数比A1、A3、A4和A5组分别降低了16.7％、28.6％、55.4％和56.9％;(4)单位面积产量和产品均匀度均在A2组达到最高.基于生长性能及养殖效能的综合评价,陆基圆池循环水养殖条件下大口黑鲈成鱼养殖阶段较适宜的养殖密度为65尾/m2.

本试验旨在通过混合青贮的方式,探究甘蔗尾或甘蔗与构树叶混合青贮对其发酵品质的影响,为改善广西地区的非常规饲料资源利用率和混合青贮饲料的实际应用提供科学依据和技术支撑.试验1:甘蔗尾与构树叶混合青贮;试验2:甘蔗与构树叶混合青贮.甘蔗尾或甘蔗与构树叶的混合比例分别为100:0、75:25、50:50、25:75、0:100.试验1结果表明:1)与甘蔗尾单独青贮相比,甘蔗尾与构树叶混合青贮显著增加了混合青贮饲料的粗蛋白质、乙酸含量(P<0.05),显著提高了有氧暴露后乙酸和丙酸的含量(P<0.05),并显著降低了肠杆菌数量(P<0.05).2)与构树叶单独青贮相比,构树叶与甘蔗尾混合青贮显著增加了混合青贮饲料的可溶性碳水化合物含量(P<0.05);25％构树叶与75％甘蔗尾混合青贮显著降低了混合青贮饲料的pH和氨态氮含量(P<0.05).试验2结果表明:1)与甘蔗单独青贮相比,甘蔗与构树叶混合青贮显著降低了混合青贮饲料的乙醇含量(P<0.05).2)与构树叶单独青贮相比,25％构树叶与75％甘蔗混合青贮显著增加了混合青贮饲料的粗蛋白质、可溶性碳水化合物、乳酸和乙酸含量(P<0.05),同时显著降低了pH、氨态氮和丁酸含量(P<0.05),并使混合青贮饲料有氧暴露后的pH更稳定,同时大幅抑制霉菌的增长.综上可知,与构树叶混合青贮时,甘蔗占比75％能显著改善混合青贮饲料的发酵品质,而甘蔗尾的占比需要超过75％才能明显改善混合青贮饲料的发酵品质.

为探究陆基圆池养殖条件下大口黑鲈适宜的日投饲率,试验设置1.6％、1.9％、2.2％、2.5％和2.8％等5个投饲率,实验池水温24.8～26.5℃,以研究不同投饲率对初始体质量为(116.00±10.68)g的大口黑鲈生长及主要养殖效能的影响.结果表明,大口黑鲈的体质量日增重率、特定生长率和单位面积产量均为B5组(日投饲率2.8％)最高,其次为B3组(日投饲率2.2％);饲料系数和变异系数组间差异不显著(P>0.05).基于主要生长指标和养殖效能参数的综合评价,在陆基圆池养殖条件下,初始体质量为(116.00±10.68)g的大口黑鲈日投饲率以2.2％为宜.

随着全国各地集约化养殖范围的不断扩大,斑点叉尾(鮰)病害发生情况日趋严重.因此,寻找开发天然、环保、安全有效的药物对斑点叉尾(鮰)的养殖具有重要的意义.穿心莲(Andrographis paniculata)含有多种生物活性成分,具有抗炎、抗菌、抗病毒等作用.目前,已有研究报道了黄芪、黄连、大黄、黄柏、杜仲、五倍子、蓖麻等传统中草药对斑点叉尾(鮰)生长和免疫性能的影响(王庆奎等,2011:简少卿等,2011;郭永军等,2012;陶莎,2020),但穿心莲对斑点叉尾(鮰)免疫方面的研究还未见报道.本试验以斑点叉尾(鮰)为研究对象,探讨在饲料中添加不同水平的穿心莲粉对其免疫性能方面的影响.

本试验旨在通过混合青贮的方式,探究甘蔗尾或甘蔗与桑叶混合青贮对其青贮品质的影响,为改善广西地区的非常规饲料资源利用率和混合青贮饲料的实际应用提供科学依据和技术支撑.试验1:甘蔗尾与桑叶混合青贮;试验2:甘蔗与桑叶混合青贮.2种青贮原料的混合比例分别为100:0、75:25、50:50、25:75、0:100.试验1结果表明:1)与甘蔗尾单独青贮相比,甘蔗尾与桑叶混合青贮显著增加了混合青贮饲料的粗蛋白质、乳酸、乙酸和丙酸含量(P<0.05).2)与桑叶单独青贮相比,桑叶与甘蔗尾混合青贮对混合青贮饲料的pH和氨态氮含量的影响较弱(P>0.05),但能降低其有氧暴露后pH和酵母菌的增长速率.因此,桑叶与甘蔗尾混合青贮更倾向于提高混合青贮饲料的有氧稳定性.试验2结果表明:1)与甘蔗单独青贮相比,甘蔗与桑叶混合青贮显著增加了混合青贮饲料的干物质、粗蛋白质、乙酸和丙酸含量(P<0.05),显著降低了乙醇含量和青贮损失(P<0.05).2)与桑叶单独青贮相比,桑叶与甘蔗混合青贮显著增加了混合青贮饲料的乳酸、乙酸含量(P<0.05),显著降低了pH、氨态氮与丁酸含量和肠杆菌数量(P<0.05),改善了混合青贮饲料的青贮品质;当25％桑叶与75％甘蔗混合青贮时,能抑制混合青贮饲料有氧暴露后的氨态氮生成,还能促进乙酸的产生,其青贮品质表现最佳.综上可知,与桑叶混合青贮时,甘蔗占比不低于25％时能改善混合青贮饲料的青贮品质;而甘蔗尾与桑叶混合青贮更倾向提高混合青贮饲料的有氧稳定性.

为研究穿心莲(Andrographis paniculata)对斑点叉尾鮰(Ictalurus punctatus)消化酶活性的影响,试验选取平均体重为(5.92±0.63)g的健康斑点叉尾鮰270尾,随机分成9组(G0、G1、G2、G3、G4、G5、G6、G7、G8组),每组设3个重复,每个重复10尾鱼,每组分别投喂添加不同比例穿心莲粉(0％、0.38％、0.75％、1.13％、1.50％、1.88％、2.25％、2.63％、3.00％)的饲料.饲养试验时间为30 d.结果发现,肠道中的消化酶,G0和G1组的脂肪酶活性显著高于其它各组(P＜0.05);G8组的淀粉酶活性最高,显著高于G0、G1、G4和G7组(P＜0.05);胰蛋白酶活性总体呈现出先上升后下降的趋势,以G6组的最高.结果表明,在斑点叉尾鮰饲料中添加1.88％～2.25％的穿心莲能提升胰蛋白酶的活性.

为研究穿心莲对斑点叉尾(鮰)生长性能的影响.设置8个试验组,每组3个重复,各试验组投喂穿心莲粉含量分别为0％,0.38％,0.75％,1.13％,1.88％,2.25％,2.63％和3.00％的饲料,试验周期为30 d.结果显示,各试验组鱼体的体质量增长率和特定生长率均随穿心莲添加量的增加呈先上升后下降的趋势,其中G4组和G5组较高,显著高于其他试验组(P＜0.05);斑点叉尾(鮰)的肥满度和肝体比也随穿心莲添加量的增加呈现出先升高后降低的趋势;G2组肥满度显著高于其他各组(P＜0.05);G1组的肝体比显著高于G0组和G7组(P＜0.05),与其他组无显著差异(P＞0.05).指出,在斑点叉尾(鮰)饲料中添加穿心莲能提高鱼体的生长性能,其中以1.88％的添加量效果最佳.

试验旨在探讨黄芪对斑点叉尾鮰生长性能和肌肉营养成分的影响.选取体重(56.40±1.60)g的健康斑点叉尾鮰600尾,随机分成4组(G0、G1、G2、G3组),每组3个重复,每重复50尾鱼,分别投喂添加不同比例(0、1％、2％、3％)黄芪的试验饵料.试验期48 d.结果显示:添加黄芪的试验组斑点叉尾鮰的增重率(WGR)和特定生长率(SGR)均显著高于对照组(P＜0.05);G2、G3组斑点叉尾鮰的肥满度显著高于对照组(P＜0.05).添加黄芪的试验组鱼体肌肉粗蛋白含量均显著高于对照组(P＜0.05);G2、G3组鱼体肌肉粗脂肪含量显著高于对照组(P＜0.05).研究表明,在斑点叉尾鮰基础饵料中添加黄芪能够有效提高鱼体的生长性能,改善肌肉品质,建议以2％的添加量效果更好.

To study the characteristics of gonadal development of Hongdu Pseudocrossocheilus bamaensis in Hongshui River, the fish samples were taken in Hongdu District, Du’an section of the Hongshui River in Guangxi from June 2020 to March 2021. The gonadal somatic index（GSI） and the condition factor were measured and calculated. The results showed that, the GSI of the female fishes fluctuated between 0.34% and 1.63%. The GSI of the male fishes fluctuated between 0.03%-0.14%. The condition factor of female fishes varied between 1.91 and2.44. The condition factor of male fishes varied between 1.88 and 2.29. The condition factor of fish showed a downward trend from summer to autumn, growing from autumn to winter, decreasing from winter to spring. The gonad weightand the condition factor of female showed significant positive correlation. The results show that, the gonads of Hongdu P. bamaensis male and female develop asynchronous time. There is greater uncertainty about intensive cultivation of parental fish in artificial breeding and the choice of oxytocin timing.

为研究不同体质量对斑点叉尾鮰(Ictalurus punctatus)幼鱼耗氧率的影响,采用封闭流水式法测定了2种不同规格(平均体质量分别为(1.80±0.05)g、(3.49±0.10)g)斑点叉尾鮰幼鱼耗氧率的变化情况.结果发现,斑点叉尾鮰幼鱼的耗氧率随着体质量的增加而降低(P＜0.05);两个处理组试验鱼晚上的平均耗氧率均显著高于白天的平均耗氧率(P＜0.05).这表明,斑点叉尾鮰幼鱼夜晚的代谢水平更高,体质量小的鱼体代谢强度更强.

采用封闭流水式装置,研究斑点叉尾幼鱼(Ictalurus Punctatus)(约9～11 g)在不同温度条件下(18,22和26℃)的耗氧率和氨氮排泄率变化情况.结果表明,在18,22和26℃时斑点叉尾幼鱼的耗氧率分别为(171.66±33)mg/(kg·h),(97.22±26)mg/(kg·h)和(171.83±44)mg/(kg·h),26℃处理组的耗氧率最高,与22℃处理组具显著差异(P<0.05);氨氮排泄率也表现出随水温的升高而升高的趋势,18,22和26℃时其氨氮排泄率分别为(0.40±0.01)mg/(g·h),(0.44±0.01)mg/(g·h)和(0.58±0.01)mg/(g·h).在22～26℃,斑点叉尾幼鱼的耗氧率和氨氮排泄率均随温度升高而升高.

试验研究了不同放养密度对黄颡鱼生长性能和水质的影响,为今后黄颡鱼的露天规模养殖提供参考.试验塘(A、B、C)水深约为2.0 m的土质塘,放养密度分别设置为每667 m2放养1.00,2.00和3.00万尾,试验持续315 d,在试验第1,109和315 d进行3次水质检测,试验结束后测定各塘黄颡鱼的生长性能指标.结果发现,随着放养密度的增加,黄颡鱼增重率和体长增长率均减小;肥满度先下降后上升;饲料系数和变异系数增大;水体中硝酸盐、亚硝酸盐、总氮和总磷的含量先上升后降低;从试验开始到第109 d,水体中硝酸盐含量都处于较低水平;试验后期,B塘水体中硝酸盐含量剧增;试验前期水体中亚硝酸盐、总氮和总磷含量稳定;中后期亚硝酸盐和总磷含量先增加后减少,总氮含量在一定范围内波动,但差异不显著.综上,放养密度增加会抑制黄颡鱼的生长,水体中亚硝酸盐增加也会导致水质恶化.

试验探究中草药复方制剂对团头鲂生长性能及肝脏组织的影响.选取平均体重为(50.00±1.80)g的健康团头鲂1050尾,随机分成7组(A1、A2、B3、B4、C5、C6、D7),每组3个重复,每个重复50尾鱼,用不同的中草药复方制剂饲料连续投喂28 d.结果显示,B4、C5和C6团头鲂的增重率(WGR)和特定生长率(SGR)显著高于对照组(D7)(P<0.05);B4、C5和C6团头鲂的饲料系数(FCR)显著低于对照组(P<0.05);B4、C5和C6组的肥满度显著高于对照组(P<0.05),且对照组的肥满度最低.对照组、A1和A2组团头鲂的肝组织在14 d后出现病变迹象,且随着投喂时间延长组织病变加重;B3、B4、C5和C6组的在28 d投喂期间均保持健康状态.研究表明,在团头鲂基础饲料中添加4％的中草药复方制剂B(以杜仲微粉为主,金盏花和黄芪微粉为辅)和2％、4％的中草药复方制剂C(以黄芪微粉为主,金盏花和杜仲微粉为辅)均能有效提高鱼体的生长性能,有助于肝组织保持健康状态.

为探究中草药复方制剂对团头鲂免疫组织形态和血液指标的影响.试验选取1050尾平均体重为(50.00±1.80)g的健康团头鲂,随机分为7组(A1、A2、B3、B4、C5、C6、D7),每组设3个重复,每个重复50尾鱼.试验分别在全价饵料配方中添加2％和4％不同的中草药复方制剂(A、B、C).试验期28 d.结果显示,对照组(D7)、A1组和A2组的团头鲂其脾、肾、肠组织在14 d后出现病变迹象,且随着投喂时间延长组织病变加重;B3组、B4组、C5组和C6组团头鲂在28 d投喂期间均保持健康状态.饲养28 d,C5、C6组团头鲂的白细胞数量显著高于对照组(P<0.05);C6组团头鲂的血红蛋白含量在14和21 d时显著高于对照组(P<0.05);C6组团头鲂的红细胞数量在试验第14、21和28 d时均为最高(P<0.05).研究表明,以金盏花、杜仲和黄芪三种天然植物为组分的复方制剂,对团头鲂的非特异性免疫功能均有不同程度的增强效果,其中以黄芪微粉为主,金盏花和杜仲微粉为辅复方制剂的增强效果最佳.

This study was explored the supplementary of vitamin E on reproduction of tilapia. Five vitamin E supplements (0, 40, 80, 120 and 160 mg/kg) were tested for 90 days. Results: The SGR, GSI and ovarian maturity of female were the highest at Group 120 mg/kg, and the FCR was the lowest. The SGR, GSI and testis maturity of male were the highest at Group 160 mg/kg, and the FCR was the lowest. The levels of FSH and P were significantly increased at Group 120 mg/kg in female, and the levels of E2 reached the maximum. The levels of T and GnRH were increased at Group 160 mg/kg in male. The expression of FSHR in female liver was the highest at Group 160 mg/kg, and the expression of FSHR in ovary was the highest at Group 40 mg/kg. The expression of FSHR and pgr in female kidney was significantly increased at Group 40 and 80 mg/kg. The expression of FSHR and pgr in testis was the highest at Group 160 mg/kg. In conclusion, vitamin E can regulate the secretion levels of reproductive hormones and the expression levels of FSHR and pgr during different developmental stages in tilapia, and thus promote tilapia reproduction and growth. Among them, the reproductive and growth performance of female tilapia were the greatest at Group 120 mg/kg, and for male tilapia, these parameters were the greatest at Group160 mg/kg.