微生态制剂对泥鳅生长性能、体成分和免疫活性的影响

以泥鳅为试验材料,将芽孢杆菌、光合细菌、EM菌比例分别为1∶2∶2和2∶1∶2的两种微生态制剂加入养殖水体,饲养大鳞副泥鳅(Misgurnus anguillicaudatus)32 d,定期测量泥鳅的生长,鱼体成分及血清溶菌酶活力和超氧化物歧化酶(SOD)活力。结果表明,试验组泥鳅的末重、增重率、日增重和饲料转化率均高于对照组;试验组泥鳅体成分粗蛋白含量高于对照组,粗脂肪含量低于对照组;在血清酶活力方面,试验组泥鳅溶菌酶活力和SOD活力高于对照组。使用微生态制剂能显著提高泥鳅养殖生长性能、改善鱼体成分、提高泥鳅血清溶菌酶活力和SOD活力。     

添加微生态制剂及投饲模式对幼刺参生长的影响

水温12～18℃,将体质量(3.37±0.15)g的仿刺参幼参饲养在容水50 L的塑料槽中,研究添加微生态制剂的饲料及不同日投喂量对幼刺参生长及养殖水质指标的影响.采用以3d日投喂量相同(1∶1∶1)及3d日投喂量不同(5∶3∶2)的投饲方式,微生态制剂饲料在基础饲料的基础上加入4.5ml有益复合微生物菌群与芽孢杆菌混合液,并于30℃水浴中预处理12 h以上而制成.60 d的试验结果表明,以投喂微生态制剂饲料组的氨氮、亚硝酸氮、化学需氧量明显低于基础饲料组;以5∶3∶2方式投喂微生态制剂饲料组的刺参质量增加率、日质量增加和特定生长率明显高于1∶1∶1方式和基础饲料组(P＜0.05);以5∶3∶2方式投喂微生态制剂饲料组的饲料表观消化率、耗氧率和排氨率较高.     

微生态制剂对银鲫免疫机能的影响

饲料中微生态制剂的添加量为1×1011/kg,即可显著提高银鲫血液白细胞吞噬活性和血清溶菌酶活性,投喂微生态制剂后第4天或第7天,PP、PI显著或极显著地高于对照组,而且在停止投喂微生态制剂10d后,试验组的PP和PI仍显著或极显著地高于对照组。投喂微生态制剂后第7天,试验组银鲫溶菌酶的活性显著或极显著高于投喂制剂前及对照组,停止投喂第10天,血清溶菌酶的活性与对照组之间即无显著差异。     

微生态制剂替代饲用抗生素对肉鸡生产性能及肠道结构影响

<正>本试验探讨日粮中添加复合微生态制剂和饲用抗生素对肉鸡生长性能及肠道组织结构的影响。选用1d龄AA肉鸡135只,随机分成3组,每组3个重复,分为对照D组、抗生素K组、复合微生态制剂T组,为期42d。研究各试验组料肉比、十二     

微生态制剂与柠檬酸合用对肉鸡盲肠和粪便中臭气化合物的影响

研究旨在观察微生态制剂与柠檬酸联合使用对肉鸡盲肠和粪便中臭气物质含量的影响。选用1日龄健康爱拔益加肉雏鸡360只,随机分成3组,每组6个重复,每个重复20只鸡。一个对照组(Ⅰ组)供给清水,Ⅱ组、Ⅲ组为试验组,分别在饮水中添加0.5‰、1‰的由微生态制剂和柠檬酸组成的配方。试验期45d。结果显示,微生态制剂与柠檬酸联合使用能在一定程度上降低动物肠道内乙酸、丙酸、丁酸等挥发性脂肪酸含量(P>0.05);能显著降低粪便中吲哚、粪臭素等臭气物质含量(P<0.05),这对微生态制剂与柠檬酸合用能提高鸡舍空气质量、改善养殖环境有一定作用。     

3种饲料添加剂对吉富罗非鱼幼鱼生长性能、消化酶活性和肝、肠组织结构的影响

为探讨中草药提取物、胆汁酸、微生态制剂对吉富罗非鱼(Oreochromis niloticus)生长性能、消化酶活性和肝、肠组织结构的影响,以基础饲料为对照,分别在每千克基础饲料中添加中草药提取物(1、2 g)、胆汁酸(0.1、0.2 g)、微生态制剂(1、2 g)配制成6种试验饲料,选取平均体质量为(32.75±5.75)g的吉富罗非鱼幼鱼483尾,随机分为7处理,每处理3平行,每平行23尾,共进行养殖实验45 d。结果显示:与对照组相比,低剂量使用此3种添加剂均有改善实验鱼生长和饲料利用的趋势。饲料中添加胆汁酸显著提高了吉富罗非鱼的增重率和特定增长率;饲料中添加微生态制剂组的吉富罗非鱼的肥满度最大,但各处理组之间差异不显著;中草药组的增重率与特定生长率与对照组之间无差异。饲料中添加微生态制剂和0.1 g/kg胆汁酸的实验鱼肠道脂肪酶活性显著高于中草药提取物2 g/kg的处理组;各组间的肠道淀粉酶、蛋白酶活性差异不显著。与对照组相比,各处理组实验鱼的前肠绒毛个数和肌肉层厚度有增加的趋势;添加1 g/kg微生态制剂的实验鱼中肠绒毛长度显著高于中草药组。结果表明:饲料中添加1 g/kg中草药提取物,0.2 g/kg胆汁酸,1 g/kg微生态制剂可在一定程度上提高吉富罗非鱼幼鱼的生长性能。     

微生态制剂对肉鸡生产性能的影响试验

将750只初生艾维茵肉鸡随机分为2个试验组和1个对照组,在2个试验组分别通过饲料、饮水添加0.2%微生态制剂(EM制剂)进行饲喂对比试验。结果表明:0.2%EM无论拌料、饮水投喂,均能减少鸡的发病率、死亡率,提高成活率和饲料报酬。     

GM微生态制剂发酵饲料饲喂生长肉猪试验报告

试验观测29头生长肉猪利用GM微生态制剂发酵饲料的生产效果。结果表明使用GM发酵全价粉料饲喂生长肉猪106d,试验猪日增重646g,饲料报酬3.08∶1;使用全价粉料的对照组猪日增重682g,饲料报酬3.08∶1,差异不显著。     

芽孢杆菌微生态制剂对灰海马幼体生长、成活率及消化酶活力的影响

通过给灰海马(Hippocampus erectus Perry)初生幼体口服卤虫包膜的芽孢杆菌微生态制剂,探讨其对海马幼体生长、成活率及消化酶活力的影响。共计3批初生的灰海马幼体(3对亲本一次产出的全部幼体),每批平均分为两组,分别作为试验组和对照组。3批幼体作为3个重复组,以排除初生幼体质量不同引起的差异。试验组投喂用芽孢杆菌微生态制剂处理过的卤虫幼体,对照组投喂未经芽孢杆菌微生态制剂处理的卤虫幼体,试验时间为25 d。试验结束时,试验组灰海马幼体体长和体长增量与对照组无显著差异;体质量方面,仅第3批中试验组显著高于对照组(P＜0.05),其它两批无显著差异;3批次试验组灰海马幼体的成活率均显著高于对照组(P＜0.05);消化酶方面,试验组与对照组间除第3批试验灰海马幼体的脂肪酶活力及第1批试验灰海马幼体的蛋白酶活力无显著差异外,其它批次中试验组灰海马肠道脂肪酶、蛋白酶和淀粉酶的活力均显著高于对照组(P＜0.05)。结果表明,口服芽孢杆菌微生态制剂能够显著提高人工养殖灰海马幼体的成活率及肠道消化酶活力。     

微生态制剂在生猪健康养殖中的示范应用观察

将112头中大猪随机分为试验组和对照组,每组56头。试验组在饲料中添加0.3%的润佛微生态制剂,对照组不添加,两组以相同饲养管理方式饲养52 d,结果显示,试验组料肉比降低、日均增重提高,整体健康状况良好,值得在健康养殖中加以研究应用。     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.     

Growth hormone (GH) and reproduction: a review

Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.     

Purification and partial characterization of GtHs (cfLH and cfFSH) from Indian walking catfish (Clarias batrachus) (L.) and development of a homologous ELISA for cfLH

Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL^?1 (1.25 ng well^?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.     

Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection

Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg^?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).     

Imported ornamental fish are colonized with antibiotic‐resistant bacteria

There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future.     

Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load

This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos.     

Nitrogenous waste excretion and accumulation of urea and ammonia inChalcalburnus tarichi (Cyprinidae), endemic to the extremely alkaline Lake Van (Eastern Turkey)

The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I^–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg^–1 fish·h^–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g^–1·ml^–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min^–1·g^–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min^–1·g^–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.     

Influence of the antibacterial herbs, Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia on the survival, growth and bacterial load of Penaeus monodon post larvae

The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 10³ to 3.76 × 10⁵ cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 10⁵ cfu/g). This revised version was published online in August 2006 with corrections to the Cover Date.