Tissue fluoride accumulation and kidney lesions in freshwater‐reared Atlantic salmon (Salmo salar) fed with high dietary fluoride concentrations     

J.Ø. HANSEN  M.H. PENN  K.D. SHEARER  T. STOREBAKKEN  M. ØVERLAND 《Aquaculture Nutrition》2012,18(3):304-312

Antarctic krill (Euphausia superba) and other marine zooplankton may contain high levels of fluoride. The aim of the present experiment was to determine whether dietary fluoride from Antarctic krill at levels similar to the old and the new EU allowable limits in fish feeds (150 and 350 mg kg^?1) would induce kidney lesions in freshwater‐reared Atlantic salmon (Salmo salar). In addition to the diets containing krill, two high‐sodium fluoride (NaF) diets (1500 and 3500 mg kg^?1) were used to investigate the effect on growth, feed intake, faecal excretion of minerals and accumulation of fluoride in various tissues. No major effects on growth or feed intake were observed. A higher proportion of the ingested fluoride was absorbed in salmon fed with the NaF diets compared with fish fed with krill shell diets. Fluoride accumulated in liver, kidney and especially bone. Faecal excretion of calcium and magnesium was higher for the NaF‐fed fish compared with fish fed with the control and krill shell diets, whereas the levels of these minerals in plasma were unaffected. Dietary fluoride from krill shells did not induce kidney lesions. One‐third of the salmon fed with the highest NaF diet showed signs of crystal formation within the distal tubules and/or collecting ducts in the kidney.  相似文献   

Importance of broodstock holding temperature on fecundity and egg quality in three groups of photo‐manipulated Atlantic cod broodstock     

Øyvind J Hansen  Velmurugu Puvanendran  Atle Mortensen 《Aquaculture Research》2012,44(1):140-150

We conducted a study to evaluate the effects of holding water temperature on the fecundity and egg quality of photo‐manipulated Atlantic cod broodstock. Adult cod Gadus morhua were distributed among several 25‐m³ tanks. Three separate photoperiods were used for each group to obtain three spawning per year (in May, July and December). While photoperiod was controlled, the temperature was not controlled and followed the ambient seasonal pattern. Due to the uncontrolled seasonal temperature used, each spawning group experienced different temperatures at a particular gonadal developmental stage. Otherwise, all groups were treated the same. Results showed that the May and July spawning groups released significantly more eggs per kg of fish (four and three times more respectively) than the December spawning group. The egg fertilization success and proportion of normal eggs were also higher in the May and July groups. Possible reason for the difference may be that the May and July groups experienced lower temperatures (4–7°C) during oocyte maturation and ovulation than the December group (7–9°C). Our results show the importance of using lower/natural temperatures during oocyte maturation and ovulation to obtain good quality eggs in photo‐manipulated cod broodstock.  相似文献   

Feeding motivation as a personality trait in Nile tilapia (Oreochromis niloticus): role of serotonergic neurotransmission     

Patricia I. M. Silva  Catarina I. M. Martins  Erik Höglund  Hans Magnus Gjøen  Øyvind Øverli 《Fish physiology and biochemistry》2014,40(5):1547-1557

Consistent individual variation in behaviour and physiology (i.e. animal personality or coping style) has emerged as a central topic in many biological disciplines. Yet, underlying mechanisms of crucial personality traits like feeding behaviour in novel environments remain unclear. Comparative studies, however, reveal a strong degree of evolutionary conservation of neural mechanisms controlling such behaviours throughout the vertebrate lineage. Previous studies have indicated duration of stress-induced anorexia as a consistent individual characteristic in teleost fishes. This study aims to determine to what degree brain 5-hydroxytryptamine (5-HT, serotonin) activity pertains to this aspect of animal personality, as a correlate to feed anticipatory behaviour and recovery of feed intake after transfer to a novel environment. Crucial to the definition of animal personality, a strong degree of individual consistency in different measures of feeding behaviour (feeding latency and feeding score), was demonstrated. Furthermore, low serotonergic activity in the hypothalamus was highly correlated with a personality characterized by high feeding motivation, with feeding motivation represented as an overall measure incorporating several behavioural parameters in a Principle Component Analyses (PCA). This study thus confirms individual variation in brain 5-HT neurotransmission as a correlate to complex behavioural syndromes related to feeding motivation.  相似文献   

Saponins and phytosterols in diets for European sea bass (Dicentrarchus labrax) juveniles: effects on growth,intestinal morphology and physiology          下载免费PDF全文

A. Couto  T.M. Kortner  M. Penn  G. Østby  A.M. Bakke  Å. Krogdahl  A. Oliva‐Teles 《Aquaculture Nutrition》2015,21(2):180-193

This study aimed to elucidate the effects of two soy antinutrients, saponins and phytosterols, on growth, intestinal health and function of European sea bass juveniles. Seven fishmeal‐based diets were formulated: a control diet without antinutrients and six experimental diets containing low or high levels of soyasaponins (SapL and SapH, respectively), low or high levels of phytosterols (PhytL and PhytH, respectively) and low or high levels of soyasaponins + phytosterols (SapPhytL and SapPhytH, respectively). A feeding trial was conducted for 59 days after which blood was collected for plasmatic cholesterol quantification and intestinal samples were collected for histology, digestive enzymes activity and gene expression analysis. Histology was also performed at day 15. PhytL resulted in high distal intestine (DI) relative weight and decreased plasma cholesterol, while PhytH caused inflammatory changes in the DI. SapH depressed maltase and alkaline phosphatase activity in DI and the histological evaluation indicated some inflammatory changes. The SapPhytH resulted in decreased maltase activity in the DI and indications of inflammatory changes that were supported by the results on gene expression profiles. The antinutrients tested did not compromise growth, however, caused some gastrointestinal disturbance that may affect fish in the long term.  相似文献   

Between- and within-site variation of density and bending properties of Picea abies structural timber from Norway     

Geir I. Vestøl  Carolin Fischer  Olav Høibø  Audun Øvrum 《Scandinavian Journal of Forest Research》2016,31(8):758-765

This study provides an analysis on the variability of structural timber of Norway spruce (Picea abies) grown in Norway. Density, modulus of elasticity (MOE) and bending strength were measured on 1188 boards from 205 trees, sampled from 14 sites throughout Southern Norway, Eastern Norway and Trøndelag. The area represents the procurement area for the majority of Norwegian sawmills. The variability of the timber properties was analysed in a linear mixed model where the random variance was divided into variance due to site, variance due to trees and within-tree variance. Models describing variance due to site based on site index, altitude and latitude were developed, and combined with data from the Norwegian National Forest Inventory to estimate mean values and variability of the timber properties. The results showed that major parts of the variance due to site are explained by altitude and site index, and for density also by latitude. Major parts of the variance due to site and the variance due to trees in bending strength and MOE were explained by density.  相似文献   

Utilization of H2SO4‐hydrolysed phosphorus from herring bone by‐products in feed for Atlantic salmon (Salmo salar) 0+ postsmolt          下载免费PDF全文

S. Albrektsen  E.‐J. Lock  G. Bæverfjord  M. Pedersen  A. Krasnov  H. Takle  E. Veiseth‐Kent  R. Ørnsrud  R. Waagbø  E. Ytteborg 《Aquaculture Nutrition》2018,24(1):348-365

The utilization efficiency of phosphorus (P) hydrolysed from herring by‐products in feed for Atlantic salmon 0⁺ postsmolt was studied. Seven diets were produced with a low P level (D1): 5 g soluble P/kg, with P hydrolysed from herring by‐products (D2, D3, D4): 7, 9 and 11 g soluble P/kg, or blue whiting fish bone meal (D5): 9 g soluble P/kg, and with P from NaH₂PO₄ (D6, D7): 9 g soluble P/kg diet. Diet D7 was also added (NH₄)₂SO₄. Fish fed D1 had significantly lower growth compared to D3, D5 and D7, morphological changes in bone consistent with low mineral contents, significantly reduced scale macromineral contents and changes in P markers, that is bone ALP and NaPi in pyloric caeca. The average P retention was 3.6 and 3.2 g P/kg weight gain, respectively, in D2–D7 and in D1. Fish fed D3, D5 and D6 showed similar growth, P digestibility, tissue mineralization, P retention and P excretion. The dietary P requirement in salmon was met between 5.1 and 7.4 g/kg soluble P (DM). This study shows that P hydrolysed from fish bones can be recycled and used as an efficient P source in feed for Atlantic salmon.  相似文献   

Ellipsomyxa gobii gen. et sp. n. (Myxozoa: Ceratomyxidae) in the common goby Pomatoschistus microps (Teleostei: Gobiidae) from Denmark     

Køie M 《Folia parasitologica》2003,50(4):269-271

A new myxosporean species Ellipsomyxa gobii gen. et sp. n. is described from the common goby Pomatoschistus microps (Kr?yer) (Perciformes, Gobiidae). Plasmodia with long branched pseudopodia in the gallbladder develop to subspherical bisporous plasmodia. The myxospores were found in the gallbladder, and the hepatic and bile ducts. The new genus is characterised by the morphology of the myxospores. The myxospores have smooth thin valves elongated in the direction perpendicular to the plane of the straight central transverse indistinct sutural line. The two spherical polar capsules open some distance from the sutural line on opposite sides. The new genus thereby differs from Leptotheca Thélohan, 1895. Ellipsomyxa gobii is tentatively placed in the Ceratomyxidae.  相似文献   

Fourier transform infrared analyses of bog and modern oak wood (<Emphasis Type="Italic">Quercus petraea</Emphasis>) extractives     

E.-M.?A.?AjuongEmail author  M.?Redington 《Wood Science and Technology》2004,38(3):181-190

Bog and modern oak wood extractives were studied to see the impact of bog conditions upon the nature of extractives using Fourier transform infrared analyses. Except for the ethanol-toluene extracts of modern oak acidic components predominate in the bogwood, ester forms prevail in modern or non-bog wood. In both cases, toluene extractives were mostly fatty acids and their esters, whilst the extracts recovered by the remaining solvents were mainly polar aromatic substances of cyclic nature. Tests revealed these components to be mainly tannins and low molecular polysaccharides.  相似文献   

Specific Pathogen‐Free Pig Herds also Free from Campylobacter?          下载免费PDF全文

E. M. Kolstoe  T. Iversen  Ø. Østensvik  A. Abdelghani  I. Secic  T. Nesbakken 《Zoonoses and public health》2015,62(2):125-130

As Specific Pathogen‐Free (SPF) pig herds are designed and managed to prevent specific pig diseases, it might be feasible to expand the list of micro‐organisms also including zoonotic pathogens such as Campylobacter coli as this agent has its origin in pigs. In a previous survey, 15 of 16 of SPF herds were found free from human pathogenic Yersinia enterocolitica. Accordingly, three nucleus and seven multiplying herds were surveyed for Campylobacter to investigate whether the Norwegian SPF pig pyramid also might be free from this agent. In conclusion, the intervention of Campylobacter at the herd level might be possible as four of 10 SPF herds tested negative in two sets of samples from both autumn 2008 and summer/early autumn 2010. The four negative herds were all located in remote areas several kilometres away from conventional pig farming while the positive SPF farms were all situated in neighbourhoods with conventional pig production. It seems more difficult to control Campylobacter than some specific animal disease agents and another significant zoonotic agent, Y. enterocolitica, in pig herds.  相似文献   

一株野大麦内生真菌的生物学与生理学特性     

陈泰祥  李春杰  李秀璋 《草业科学》2016,33(9):1658-1664

本研究对野大麦(Hordeum brevisubulatum)内生真菌(Epichlobromicola)菌株WBE1的生物学与生理学特性进行了研究。结果表明,内生真菌WBE1最适生长温度为22~25℃,4℃和35℃停止生长,最适生长pH为5.09~6.10的中性偏酸环境,对碳源的利用能力由强到弱依次为麦芽糖D-山梨糖甘露醇蔗糖乳糖可溶性淀粉葡萄糖D-果糖,D-木糖抑制其生长;对可利用氮源的利用能力由强到弱依次为胰蛋白胨牛肉膏蛋白胨酵母浸粉L-甲硫氨酸L-苯丙氨酸亮氨酸,不能利用硝酸钾、脯氨酸、草酸铵,钼酸铵抑制其生长,光照对菌丝生长无影响,CMA、OMA、PSA和PDA是菌丝生长较适宜的培养基,在WBA培养基上40d左右开始生长。菌株在PDA的前6周的生长速率呈增长趋势,第6周达最大值,第7周开始生长速率逐渐变小。  相似文献