The role of dietary methionine concentrations on growth,metabolism and N‐retention in cobia (Rachycentron canadum) at elevated water temperatures     

Minh Van Nguyen  Marit Espe  Louis E. C. Conceio  Hoang Minh Le  Manuel Yúfera  Sofia A. D. Engrola  Ann‐Elise Olderbakk Jordal  Ivar Rnnestad 《Aquaculture Nutrition》2019,25(2):495-507

This study determined impacts of dietary methionine concentrations at two temperatures on growth, feeding efficiency and N‐metabolites in juvenile cobia. Methionine concentrations of the experimental diets were deficient (M9; 9 g/kg), sufficient (M12; 12 g/kg) and surplus (M16, 16 g/kg). Water temperature was normal (30°C) or elevated (34°C). Twenty cobia in triplicate tanks were fed the experimental diets for 6 weeks. Both methionine and temperature affected cobia's growth and feeding efficiency. Cobia fed M9 performed lower than the fish fed M12 and M16 diets. Additionally, cobia reared at 34°C performed poorer than at 30°C, probably due to lower voluntary feed intake in the fish reared at 34°C. Protein efficiency ratio and protein productive value in cobia fed M9 diet were less than M12 or M16 diets. This was confirmed with the improved retentions of indispensable amino acids (AAs). No interactions between methionine and temperature were observed in growth and protein accretion. At 30°C, CF improved, while HSI and VSI declined upon methionine supplementation levels. Of which an interaction between temperature and methionine was present. Plasma, muscle and liver free AA and N‐metabolites were affected by methionine and temperature. Furthermore, temperature affected cobia's lipid class composition, resulting in increased phospholipids and cholesterol at 34°C.  相似文献   

Use of reflex indicators for measuring vitality and mortality of the snow crab (Chionoecetes opilio) in captivity     

Philip James  David Izquierdo‐Gmez  Sten I. Siikavuopio 《Aquaculture Research》2019,50(4):1321-1328

The snow crab (Chionoecetes opilio) is one of the most important commercial crabs in the world; it is heavily exploited in Atlantic Canada, Alaska, the Sea of Japan and the Barents Sea. Catches in the Barents Sea north of Norway have increased dramatically in the last decade. Most of the world's catch is processed, frozen and exported overseas. However, recently there has been considerable interest in exporting live snow crab, particularly in Norway. The stress of capture and live transport can result in significant mortalities. In order to establish a live export industry for snow crab, the welfare of the animal must be monitored throughout all the steps of the live transport process. In this study the reactions of snow crabs exposed to increasing periods of air exposure were measured in terms of reflex indicators, incidence of mortality, blood lactate levels and blood protein and haemocyanin. Although this is not a specific live holding or live transport process the aim was to test the suitability of reflex indicators to reflect vitality (stress) and not just to predict mortality. This would be compared with traditional blood biochemistry techniques for measuring crustacean stress. The study demonstrated that the reflex index score (RIS) is suitable to assess the vitality of snow crab. Longer air exposure periods render higher mortality rates and less vital individuals. The authors believe using vitality reflex indicators would be a suitable way of measuring crab welfare during the live holding and transport process.  相似文献   

Coldwater RAS in an Arctic charr farm in Northern Norway     

Steinar Skybakmoen  Sten Ivar Siikavuopio  Bjrn-Steinar Sther 《Aquacultural Engineering》2009,41(2):114-121

Use of coldwater recirculating aquaculture systems (RAS) are still very rare in Norway, and only two farms are producing Arctic charr. This project took place in one of these commercial Arctic charr farms; Villmarksfisk AS in Bardu, Northern Norway.The farm gets its make-up water from ground water that holds 5 °C year around. Temperature in the rearing water varies between 7.5 °C (“low”) to 12 °C (“high”) through the year. The biological filter in the RAS seems to work stable at both “low” and “high” temperatures, including after incidents when feeding has been stopped for a day and started on top again the day after. Such an extreme change in loading was measured as a 70% increase in TAN concentration, with only minor changes in nitrite levels recorded. The biofilter also kept the nitrite stable and low in spite of diurnal variation in TAN excretion at normal feeding regimes (every day in three periods at day-time).The farming concept is to stock the farm with wild caught juvenile fish for on-growing to market size fish (0.75–1.00 kg). A drop in growth rate during early autumn has been a main concern for the farm. This may reflect a seasonal shift in growth potential, sometimes referred to as “autumn depression”. Interestingly, there is little sign of seasonal changes in the growth of hatchery-produced fish tested in the farm. Sampling of water quality through the seasons in tanks holding fish undergoing such growth depressions indicate that TAN excretion is much higher per kg feed used in the wintertime than in the springtime. This observation corresponds with the lack of weight gain during wintertime despite that the fish is feeding. Thus, feed conversion calculations indicate that feed utilization also varies with season reaching its nadir during this period.Both challenges concerning RAS in cold water and strongly reduced growth in autumn and winter time, have been investigated from 2005 to 2007 in a project financed by the Norwegian research council and the partners in the agricultural framework agreement.  相似文献   

Is the winter period a severe bottleneck of anadromous riverine Arctic charr parr?     

S. I. Siikavuopio  R. Knudsen  A. C. Winger  R. Kristoffersen 《Ecology of Freshwater Fish》2009,18(1):126-131

Abstract –  Winter growth and survival of wild individually tagged juvenile Arctic charr (1+ age) from a riverine anadromous stock, were studied in a small ice-covered (∼6 months) ground water brook (temperature ∼1 °C) connected to Skibotnelva in subarctic northern Norway. The overall winter survival was estimated to be 68% from late October 2005 to early May 2006. The recaptured charr were not significantly different in initial length or weight compared with the nonrecaptured fish suggesting low size-dependent mortality. The majority (98%) of the recaptured charr showed significant increase in size, with a mean increment of 62% from their initial bodyweight and 12% of the charr parr had more than doubled their weight. The mean specific growth rate was calculated to be slightly lower (0.27) than estimated values from a growth model (∼0.35). In addition, the condition factor increased significantly during the field experiment. These results are the first individual growth data on riverine anadromous Arctic charr parr under natural winter conditions, and indicate that charr can grow relatively fast during periods with low temperature and also that ground water brooks can be good over-wintering habitat for juvenile Arctic charr. These results suggest that the winter period is perhaps a less severe bottleneck than previously recognised for the cold-adapted Arctic charr.  相似文献   

Effects of Dietary Digestible Protein and Energy Levels on Growth Performance,Feed Utilization,and Body Composition of Juvenile Permit,Trachinotus falcatus (Linnaeus, 1758)          下载免费PDF全文

Huy Quang Nguyen  Thiet Chi Chu  Thuy Thi Le Nguyen  Ivar Lund 《Journal of the World Aquaculture Society》2018,49(5):943-952

A 9‐wk study was conducted to evaluate the effect of dietary protein and energy on growth performance of juvenile permit, Trachinotus falcatus, growing from approximately 30 to 150 g. Nine experimental diets were formulated to contain three levels of crude protein (400, 450, and 500 g/kg dry matter [DM]); and three levels of crude lipid (100, 200, and 300 g/kg DM) in a 3 × 3 factorial design. Growth rate and feed efficiency were significantly improved with increasing dietary protein levels from 400 to 500 g/kg and with dietary lipid levels from 100 to 200 g/kg. Fish body protein content was positively correlated with dietary ratio of digestible protein (DP) to digestible energy (DE) (P < 0.01, R² = 0.83), while body lipid was negatively correlated with dietary DP/DE (R² = 0.55, P < 0.05) but positively correlated with dietary DE levels (R² = 0.66, P < 0.01). Results showed a protein‐sparing effect, as protein retention was significantly increased by increasing dietary lipid level. In conclusion, the diet containing DP of 392.7 g/kg and DE of 18.8 MJ/kg (DM), corresponding to a DP/DE of 20.9 g/MJ, is suggested as an optimal feed for growth and feed efficiency in juvenile permit.  相似文献   

Climatic response and impacts of drought on oaks at urban and forest sites     

Sten Gillner  Juliane Vogt  Andreas Roloff 《Urban Forestry & Urban Greening》2013,12(4):597-605

This study focuses on the climate and growth response of the sessile oak (Quercus petraea (Matt.) Liebl.) and the northern red oak (Quercus rubra L.) using dendrochronological methods. Tree-ring series of street trees in the city of Dresden, Germany and in a nature reserve close to the urban area were analysed, and the climate and growth response and moving correlation functions (CF) were computed. Moreover, the impact of 13 years of drought was examined by superposed epoch analysis (SEA). Our results show that differences emerge from peculiarities of the different site conditions, indicating that city oaks contain a higher level of noise in their ring width data due to human activities that degrade the strength of growth-climate associations. Importantly, climatic conditions during the previous summer and autumn and during the current spring season display significant correlations with annual growth. The stability of the climate–growth relationship was tested via moving correlation functions. A strong increase in the correlation with the temperature and precipitation in April was found for the trees of northern red oak in forests. Drought years induced significant reductions in radial growth for the northern red oak only. Nevertheless, the long-term impact of drought years must be considered as marginal because of the fast recovery of the radial growth after one to two years. In the future, the growth of the northern red oak may be restricted by an increased frequency of droughts and warmer and drier conditions in April.  相似文献   

A lineage of myeloid cells independent of Myb and hematopoietic stem cells   总被引：1，自引：0，他引：1  

Schulz C  Gomez Perdiguero E  Chorro L  Szabo-Rogers H  Cagnard N  Kierdorf K  Prinz M  Wu B  Jacobsen SE  Pollard JW  Frampton J  Liu KJ  Geissmann F 《Science (New York, N.Y.)》2012,336(6077):86-90

  相似文献   

The zebrafish cationic amino acid transporter/glycoprotein-associated family: sequence and spatiotemporal distribution during development of the transport system b0,+ (slc3a1/slc7a9)     

Ellingsen  Ståle  Narawane  Shailesh  Fjose  Anders  Verri  Tiziano  Rønnestad  Ivar 《Fish physiology and biochemistry》2021,47(5):1507-1525

Fish Physiology and Biochemistry - System b0,+ absorbs lysine, arginine, ornithine, and cystine, as well as some (large) neutral amino acids in the mammalian kidney and intestine. It is a...  相似文献   

The Effects of Peptide-Precipitating Lignosulphonic Acids on the Proteolytic Activity of Pepsin in Vitro and on the Response of Pigs to an Ulcer Inducing Diet     

Bjrn Nss  Ola Westbye  Kjell Ivar Hildrum  Inger Nafstad 《Acta veterinaria Scandinavica》1973,14(1):44

The inhibitory effect of peptide-precipitating lignosulphonic acids on the proteolytic activity of pepsin in vitro has been studied. When an unfractionated lignosulphonic acid preparation was used, total inhibition of the activity of 5 µg crystalline pepsin was obtained by addition of about 15 mg of lignosulphonic acids.The greatest inhibitory effect was seen with the high-molecular weight lignosulphonic acids, but an effect was also seen with middle-and low-molecular weight lignosulphonic acids.A reduction in the inhibitory effect was seen when the experiments were performed in the presence of arginine. The inhibition mechanism is discussed in relation to the peptide-precipitating ability of the lignosulphonic acids.No obvious protection against the appearance of stomach ulcers in four pigs receiving an ulcerogenic diet was seen.  相似文献   

Risk factors for infection of sow herds with porcine reproductive and respiratory syndrome (PRRS) virus   总被引：10，自引：0，他引：10  

Mortensen S  Stryhn H  Søgaard R  Boklund A  Stärk KD  Christensen J  Willeberg P 《Preventive veterinary medicine》2002,53(1-2):83-101

In 1992, the porcine reproductive and respiratory syndrome virus (PRRSV) of European type (PRRSV-EU) was introduced in Denmark. By 1996, the virus had spread to approximately 25% of the Danish herds. In January 1996, a modified-live vaccine based on the American type of the virus (PRRSV-US) was used in replacement boars for Danish artificial insemination (AI) centres and from July 1996, the vaccine was used in PRRSV-EU infected herds for prevention of disease. Soon after vaccine introduction, PRRSV non-infected herds experienced outbreaks of disease due to infection with PRRSV-US. In this study, we investigated the risk factors (biosecurity level, animals, exposure from PRRSV-US-infected neighbour herds, semen, herd size, pig density and herd density) for infection with PRRSV-US in a cohort of 1071 sow herds; we used a nested case-control study. The retrospective observation period lasted from June 1996 (when they all were non-infected) to October 1997. Seventy-three non-vaccinated, closed sow herds became infected with the vaccine strain during this period. Each case herd was matched with two control herds from the cohort (controls had not been infected at the time of infection in the case herds). The data were analysed using a Cox-regression model. The hazard of infection increased significantly with exposure from PRRSV-US-infected neighbouring herds, purchase of animals from herds incubating PRRSV-US infection, increasing herd size and purchase of semen from boars at PRRSV-US-infected AI centres. The results are consistent with the modified-live vaccine strain spread to other herds by trade with animals and semen and by neighbour (area) transmission. We suggest that virus spread by aerosols was a frequent mode of transmission.  相似文献