草鱼出血病病毒对其它鱼的感染性研究

用草鱼出血病病鱼分离出的草鱼出血病病毒(Grass carp hemorrhage virus,GCHV)感染其它常见鱼并用ELISA方法检查感染鱼组织提取液,结果表明:青鱼、鲢鱼、布氏鳌条对GCHV抗体呈阳性反应;鲤鱼、鳙鱼、鲫鱼、团头鲂、泥鳅则呈阴性反应。综合感染鱼发病症状及死亡特征,初步认为:青鱼对GCHV是易感的,GCHV能在鲢鱼、布氏蟹条体内增值,但毒力较低,鳙鱼、鲫鱼、团头鲂、鲤鱼、泥鳅能抗GCHV感染。     

植酸酶对草鱼和新吉富罗非鱼消化酶活性的影响

植酸酶能水解植酸络合物,释放被植酸束缚的各种营养因子,因此能有效解除植酸与内源性消化酶的结合,促进消化酶的作用。本实验在全植物性饲料中添加植酸酶,研究其对草鱼(Ctenopharyngodon idellus)和新吉富罗非鱼(Oreochromis niloticus)淀粉酶及蛋白酶比活力的影响。以全植物性饲料为阴性对照组,添加磷酸氢钙(dibasic calcium phosphate,DCP)实验组为阳性对照组,另设4个不同梯度的植酸酶实验组(250 U/kg、500 U/kg、1 000 U/kg和2 000 U/kg)。实验选取健壮、规格齐整平均体质量为(12.59±0.09)g的草鱼和平均体质量为(9.59±0.12)g的新吉富罗非鱼,分别随机分为6个组,每组5个平行,每个平行20尾鱼。养殖8周后,草鱼平均体质量(18.29±0.63)g,新吉富罗非鱼平均体质量为(24.68±1.34)g,抽样取出胃、肠和肝胰脏用来分析淀粉酶和蛋白酶比活力。结果表明,植酸酶对无胃鱼草鱼和有胃鱼罗非鱼淀粉酶及蛋白酶比活力都有显著的促进作用。相比较而言,植酸酶对罗非鱼的应用效果较明显,低剂量就能显著提高其淀粉酶及蛋白酶比活力(P<0.05)。当植酸酶添加量达到1 000 U/kg时,草鱼和罗非鱼淀粉酶及蛋白酶比活力均达到峰值,此时,罗非鱼淀粉酶和蛋白酶比活力与阳性对照组无显著差异(P>0.05),而草鱼肝胰脏蛋白酶比活力显著高于阳性对照组(P<0.05)。植酸酶2 000 U/kg实验组,罗非鱼淀粉酶和蛋白酶比活力与1 000 U/kg植酸酶实验组无显著差异(P>0.05),但草鱼肝胰脏蛋白酶比活力显著低于1 000 U/kg植酸酶实验组(P<0.05)。因此,本实验条件下,植酸酶在草鱼和新吉富罗非鱼全植物性蛋白质配合饲料中的适宜添加量均为1 000 U/kg,生产实践中可通过添加植酸酶部分替代无机磷源。     

Effect of Concentrate Crude Protein Level on Grass Silage Intake,Milk Yield and Nutrient Utilisation by Dairy Cows in Early Lactation

Twenty-one multiparous dairy cows were fed concentrates containing three levels (119, 154 and 191g/kg DM) of crude protein (CP) during the first ten weeks of lactation. Part of the grain and molassed sugar beat pulp was substituted with 0% (RSM0), 15% (RSM15) or 30% (RSM30) rapeseed meal. Wilted grass silage was fed ad libitum after calving. The average response between RSM0 and RSM15 was +1.66kg milk/d per percentage unit change in concentrate CP content. No further response occurred between RSM15 and RSM30. The positive effect of RSM inclusion was seen throughout the experimental period and was associated with increased plasma non esterified fatty acids (NEFA) and decreased plasma insulin concentration one week after calving, and higher efficiency of metabolisable energy utilisation for milk production. Digestibility of the diet remained unaffected. Milk and plasma urea tended to increase with RSM30 indicating excessive supply of rumen degradable protein. Because of the limited potential of cows to compensate for a deficit in feed protein supply by mobilising tissue protein, a substantial milk yield response can be achieved with a moderate level of protein supplementation during early lactation.     

Metabolism, Intake, and Digestibility of Lambs Supplemented with Organic Chromium

The aim of the present study was to evaluate the metabolism of organic chromium and its effect on digestibility and intake of lambs. Four 4-month-old male lambs, each weighing 28 kg, were used. The animals were kept in metabolic cages for a period of 20 days (15 days of adaptation and 5 days of experimentation), in two experimental phases, with inverted treatments. Organic chromium was administered by intraruminal infusion of 1 mg of chromium-rich yeast (Saccharomyces cerevisiae) throughout the adaptive and experimental period. The dry material rates of the diet and feces of the animals were evaluated to estimate consumption, digestibility, and fecal production. During the experimental period, blood, feces, and urine were collected every 24 h to determine chromium levels. There was no significant difference in the excretion of chromium in the urine, and no mineral remnants were detected in the blood. Excretion was generally fecal. There was greater excretion of chromium in the feces of lambs in the treated group on day 0 and day 3, compared with the control group. The use of organic chromium promoted an increase in the consumption of dry material in the treated animals only at day 0 (P?<?0.05). The production of fecal dry matter was greater among the treated lambs than among the animals of the control group on day 1, day 2, day 3, and day 4 (P?<?0.05). The results obtained showed that organic chromium associated with live yeasts is not absorbed by the body and do not affect the intake time in the dose used.     

草鱼早期胚胎表面分化的细胞学研究

本文应用扫描电镜对草鱼的受精卵、2-细胞—囊胚期胚胎细胞的表面分化进行了形态学观察,结果表明,在受精卵卵膜上具有纵多的卵膜孔;受精卵质膜、2-32细胞胚胎质膜上均具有隆起和突起;在2、4、16-细胞期胚胎和囊胚表面发现有小孔结构.本文对某些结构特征进行了讨论.     

The Association Between Cytokines and Intestinal Mucosal Immunity Among Broilers Fed on Diets Supplemented with Fluorine

Fluorine (F) bioaccumulation has been reported in the organs and tissues of organisms, including intestine. The intestinal mucosa is very important to the immune development. Meanwhile, cytokines are present in the normal intestinal mucosal and play an important role in the immune function. Thus, changes of the cytokine contents are related to the state of intestinal mucosal immunity. In this study, we investigated the changes in contents of cytokines such as interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6), interferon gamma (IFN-γ), and tumor necrosis factor-alpha (TNF-α) induced by dietary high F in the mucosa of different parts of intestines (duodenum, jejunum, and ileum) by enzyme-linked immunosorbent assay. A total of 280 one-day-old healthy avian broilers were randomly divided into four groups and fed on a corn–soybean basal diet as control diet (F 22.6 mg/kg) or the same basal diet supplemented with 400, 800, and 1,200 mg?F/kg (high F groups I, II, and III) in the form of sodium fluoride for 42 days. The experimental data showed that the contents of IL-2, IL-4, IL-6, IFN-γ, and TNF-α in the intestinal mucosa were significantly decreased in the high F groups II and III when compared with those of the control group from 14 to 42 days of age. It was concluded that dietary F in the range of 800–1,200 mg/kg significantly reduced the contents of aforementioned cytokines in the intestinal mucosa of broilers, which could impact the function of intestinal mucosal immunity through the pathways that decreased the lymphocyte population and/or lymphocyte activation.     

Changes of the Serum Cytokine Contents in Broilers Fed on Diets Supplemented with Nickel Chloride

Cytokines are immunoregulatory proteins which play an important role in the immune system. The purpose of this study was to examine the serum cytokine contents including interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10), interferon gamma (IFN-γ), and tumor necrosis factor-alpha (TNF-α) induced by dietary nickel chloride in broilers by enzyme-linked immunospecific assay. A total of 240 one-day-old avian broilers were divided into four groups and fed on a corn–soybean basal diet as control diet or the same basal diet supplemented with 300, 600, and 900 mg/kg of nickel chloride. During the experimental period of 42 days, the results showed that the serum IL-2, IL-4, IL-6, IL-10, IFN-γ and TNF-α contents were lower (p?<?0.05 or p?<?0.01) in the 300, 600, 900 mg/kg groups than those in the control group. It was concluded that dietary nickel chloride in the range of 300 to 900 mg/kg could reduce the serum cytokine contents, which could finally impact the immune function in broilers.     

海南野生禾本科牧草种质资源调查、收集与鉴定

2005年11月-2006年3月对海南省19个市县分布的禾本科牧草资源进行了调查、收集与整理,本次调查共收集到禾本科植物74个属、159种,分别占海南禾本科种质资源属数的73.27%和种数的77.56%,其中《海南植物志》未记载的有4个属、21个种。本文对调查和收集的资源种类、分布情况、营养价值进行了分析,并对牧草资源的保护进行了讨论。     

草鱼出血病病毒基因组体内转录的研究

本文采用α-[~(32)p]ATP标记物在鱼肾细胞系(CIK)系统中,对草鱼出血病病毒(Grass carp hemorrhage virus,GCHV)基因组进行了体内转录的研究。通过放线菌素D抑制宿主细胞基因组的转录活动,从感染病毒细胞中分离出病毒的mRNA,分别采用液相杂交和Nortbern blot方法检查病毒mRNA的转录情况。试验结果表明,GCHV含有内源性转录酶,其基因组的转录活动是在病毒感染细胞后4小时开始,由早期基因所转录,8—10小时获得晚期基因的转录产物。这些mRNA的大小、数目大体上与病毒基因组一致。     

关于草鱼肠炎微生态调节的研究

对健康草鱼肠道菌、患肺炎病草鱼肠道菌进行菌群分析,发现正常草鱼肠道中有气单胞菌(Aeromonas)、哈夫尼亚菌(Hafnia)、黄杆菌属(Flavobacterium)等多种菌,肠炎病鱼肠道中一般仅有气单胞菌的单一菌群。拮抗试验表明哈夫尼亚菌与气单胞菌之间有一定的拮抗性。回归试验表明哈夫尼亚菌无致病性,3种气单胞菌有致病性。微生态治疗试验表明哈夫尼亚菌对患肠炎病的草鱼肠道有促进肠道微生态平衡作用。     

Changes of IgA+ Cells and Cytokines in the Cecal Tonsil of Broilers Fed on Diets Supplemented with Vanadium

The cecal tonsil of broiler is known as a secondary lymphoid tissue, which is involved in antigen-specific humoral immune responses. The purpose of this study was to investigate the effects of dietary vanadium on the tissue distribution and quantity of immunoglobulin A-positive (IgA(+)) cell in the cecal tonsil by immunohistochemistry. Simultaneously, the changes in interleukin-6 (IL-6), interleukin-10 (IL-10), interferon gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) contents in the cecal tonsil were also quantified by enzyme-linked immunosorbent assay (ELISA). A total of 420 one-day-old avian broilers were divided into six groups and fed on a corn-soybean basal diet (control diet) or the same diet supplemented respectively with 5, 15, 30, 45, and 60 mg/kg of vanadium in the form of ammonium metavanadate for 42 days. The results showed that the population of the IgA(+) cells in the cecal tonsil were significantly lower (p < 0.05 or p < 0.01) in the 45 and 60 mg/kg groups than that in the control group. Meanwhile, IL-10, IFN-γ and TNF-α contents in the cecal tonsil were significantly decreased (p < 0.05 or p < 0.01) in the 30, 45 and 60 mg/kg groups in comparison with those of the control group. However, IL-6 content in the cecal tonsil was only decreased (p < 0.05 or p < 0.01) in 60 mg/kg at 14 and 28 days of age. In conclusion, dietary vanadium in excess of 30 mg/kg reduced the numbers of the IgA(+) cells and changed the contents of the abovementioned cytokines in the cecal tonsil, which may finally impact the function of local mucosal humoral immunity in broilers.     

The prediction of intake potential and organic matter digestibility of grass silages by near infrared spectroscopy analysis of undried samples

A study was undertaken to examine a range of sample preparation and near infrared reflectance spectroscopy (NIRS) methodologies, using undried samples, for predicting organic matter digestibility (OMD g kg⁻¹) and ad libitum intake (g kg⁻¹ W^0.75) of grass silages. A total of eight sample preparation/NIRS scanning methods were examined involving three extents of silage comminution, two liquid extracts and scanning via either external probe (1100-2200 nm) or internal cell (1100-2500 nm). The spectral data (log 1/R) for each of eight methods were examined by three regression techniques each with a range of data transformations. The 136 silages used in the study were obtained from farms across Northern Ireland, over a two year period, and had in vivo OMD (sheep) and ad libitum intake (cattle) determined under uniform conditions. In the comparisons of the eight sample preparation/scanning methods, and the differing mathematical treatments of the spectral data, the sample population was divided into calibration (n = 91) and validation (n = 45) sets. The standard error of performance (SEP) on the validation set was used in comparisons of prediction accuracy. Across all 8 sample preparation/scanning methods, the modified partial least squares (MPLS) technique, generally minimized SEP's for both OMD and intake. The accuracy of prediction also increased with degree of comminution of the forage and with scanning by internal cell rather than external probe. The system providing the lowest SEP used the MPLS regression technique on spectra from the finely milled material scanned through the internal cell. This resulted in SEP and R² (variance accounted for in validation set) values of 24 (g/kg OM) and 0.88 (OMD) and 5.37 (g/kg W^0.75) and 0.77 (intake) respectively. These data indicate that with appropriate techniques NIRS scanning of undried samples of grass silage can produce predictions of intake and digestibility with accuracies similar to those achieved previously using NIRS with dried samples.     

Effect of Feed Intake and Dietary Vitamin a Levels on Sheep Performance

Abstract

A study was conducted on 20 “Rahmani” male lambs of 16 kg body weight fed on normal feed level and high vitamin A level (NF-HV); normal feed level and normal vitamin A level (NF-NV); low feed level and high vitamin A level (LF-HV) or low feed level and normal vitamin A level (LF-NV) till slaughter weight of 35–40 kg. Average daily gains of lambs were 211, 148, 117 and 87 g for the NF-HV, NF-NV, LF-HV and LF-NV groups, respectively. The corresponding feed conversions were 4.3, 5.9, 5.0 and 6.4 kg DM/kg gain. Raising feed intake and vitamin A level enhanced nutrients digestibility and nitrogen balance. Rumen liquor reflected higher pH value in animals fed higher intake (NF) in the first two diets. Both feed intake and vitamin A levels enhanced volatile fatty acids and ammonia concentrations in the rumen liquor. Feed intake and vitamin A levels positively affected haemoglobin content, packed cell volume, glucose, urea, total protein, vitamin A, insulin, cholesterol, phospholipids, glutamate oxaloacetate and glutamate pyruvate transaminases and alkaline phosphatase in blood. Vitamin A, insulin, cholesterol and phospholipids in blood increased gradually over the experimental period. Dressing percentages were 56.2, 49.6, 49.1 and 44.6% for the experimental groups, respectively. Liver content of glycogen and vitamin A increased with increasing feed intake and vitamin A levels. It is concluded that higher levels of vitamin A supplementation (than usually recommended) is required during fattening of lambs. Low energy and normal vitamin A levels are not recommended in lambs feeding.     

CaPKR-like在鲫鱼与草鱼组织中的表达特性分析

摘要：PKR是由干扰素诱导的最重要的抗病毒蛋白之一,能抑制细胞和病毒蛋白的合成。鲫鱼PKR基因(CaPKR-like)是鱼类第一个,也是非哺乳类脊椎动物第一个报道的PKR全长cDNA序列。本研究制备了CaPKR-like N-端包含Za结构域的多克隆抗体,采用Western blots检验PKR-like在鲫鱼和草鱼组织中的表达特性。Western blots显示在未诱导的鲫鱼和草鱼中该基因表达水平非常低,但是经Poly I:C免疫一周后,在鲫鱼和草鱼等8种组织中有较强的PKR-like蛋白产生。结果暗示：CaPKR-like与哺乳类PKR有相同的组织表达特性。。     

Generation and Analysis of ESTs from the Grass Carp,Ctenopharyngodon idellus

Grass carp, Ctenopharyngodon idellus (Valenciennes, 1844), is an economically important species widely cultured in the world, but its genome research resources are largely lacking. The objectives of this study were to construct normalized cDNA libraries for efficient EST analysis, to generate ESTs from these libraries, and to identify EST-related molecular markers such as microsatellites and single nucleotide polymorphisms (SNPs) for genetic analysis of this species. A total of 6,269 ESTs were generated representing 4,815 unique sequences, from which 105 putative microsatellites and 5,228 SNPs were identified. These genome resources provide the material basis for future genetic and functional analyses in this species.     

Role of 5-HT3 Receptor on Food Intake in Fed and Fasted Mice

Background

Many studies have shown that 5-hydroxytryptamine (5-HT) receptor subtypes are involved in the regulation of feeding behavior. However, the relative contribution of 5-HT₃ receptor remains unclear. The present study was aimed to investigate the role of 5-HT₃ receptor in control of feeding behavior in fed and fasted mice.

Methodology/Principal Findings

Food intake and expression of c-Fos, tyrosine hydroxylase (TH), proopiomelanocortin (POMC) and 5-HT in the brain were examined after acute treatment with 5-HT₃ receptor agonist SR-57227 alone or in combination with 5-HT₃ receptor antagonist ondansetron. Food intake was significantly inhibited within 3 h after acute treatment with SR 57227 in fasted mice but not fed mice, and this inhibition was blocked by ondansetron. Immunohistochemical study revealed that fasting-induced c-Fos expression was further enhanced by SR 57227 in the brainstem and the hypothalamus, and this enhancement was also blocked by ondansetron. Furthermore, the fasting-induced downregulation of POMC expression in the hypothalamus and the TH expression in the brain stem was blocked by SR 57227 in the fasted mice, and this effect of SR 57227 was also antagonized by ondansetron.

Conclusion/Significance

Taken together, our findings suggest that the effect of SR 57227 on the control of feeding behavior in fasted mice may be, at least partially, related to the c-Fos expression in hypothalamus and brain stem, as well as POMC system in the hypothalamus and the TH system in the brain stem.     

Detailed Dimethylacetal and Fatty Acid Composition of Rumen Content from Lambs Fed Lucerne or Concentrate Supplemented with Soybean Oil

Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18∶1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18∶2n−6 and 18∶3n−3. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18∶0 might be produced during biohydrogenation of the 18∶3n−3.     

中草药复方对草鱼鱼种肠道菌群与血液有形成分的影响

目的探讨中草药复方对鱼种肠道菌群和血液有形成分的影响。方法以草鱼鱼种为动物模型,分别采用平板倾注法和ATB半自动化细菌鉴定法,测定投喂中草药复方药饵前、后鱼种肠道菌群数量及其优势菌群种类。同时使用常规计数法和改良沙利法,测定鱼种血液中红细胞、白细胞和血红蛋白的含量。结果对照组鱼种肠道内的细菌总数为6．6×10^8CFU／g,其优势菌群为气单胞菌、假单胞菌和肠杆菌;投喂2．5％、5．0％和7．5％中草药复方药饵10d后,其肠道内细菌总数均有所减少,分别为3．0×10^7CFU／g、5．0×10^6CFU／g和1．5×10^7CFU／g,其优势菌群为吲哚黄杆菌、产碱假单胞菌和野油菜黄单胞菌。实验组与对照组鱼种的红细胞数量差异无显著性,但白细胞与血红蛋白的含量差异有非常显著性（P〈0．01）。结论以黄连、大黄、金银花、连翘、黄芪和甘草组成的中草药复方对鱼种肠道菌群和血液有形成分均有一定影响,表现出该复方具有较好的免疫抗病作用。     

草鱼呼肠孤病毒在CIK细胞中复制及形态发生的研究

以草鱼呼肠孤病毒（ＧＣＲＶ）感染的草鱼肾细胞系（ＣＩＫ）为模型,进行了草鱼呼肠孤病毒在细胞内的形态发生的研究。当病毒以感染复数为５￣１０ＰＦＵ／ＣＥＬＬ感染ＣＩＫ细胞时,在病毒感染细胞４ｈ以内的切片中,可观察到脱去部分外层衣壳的不完整病毒颗粒。感染细胞８ｈ,可观察到浆胞内病毒发生基质,其内含有大量的直径约５０ｎｍ的亚病毒颗粒,无外层蛋白结构。感染１２￣１６ｈ后,这些亚病毒颗粒装配上外层蛋白结构,形