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Smoking represents one of the oldest thermic processing methods of fish, and it was originally used to preserve fish for later meals, delaying spoiling. The objective of this study was to analyze the physicochemical and microbiological safety and quality of two traditionally smoked trout species (Oncorhynchus mykiss and Salvelinus fontinalis). We analyzed the effect of trout processed by traditional smoking, characterizing the samples according to the relationships existing between classical microbial analysis, physicochemical parameters, and the content of polycyclic aromatic hydrocarbons (PAHs). The microbial activity of the smoked fish was very low. Although traditional smoking implies high temperatures and direct exposure to the smoke, Benzo[a]pyrene, Benzo[b]fluoranthene, Benzo[k]fluoranthene, Dibenzo[a,h]anthracene, Benzo[g,h,i]perylene, and Indeno [1,2,3-cd]pyrene compounds had undetectable levels in the samples. The products obtained in this study did not exceed the maximum values imposed by EU legislation regarding the TVB-N values during the 30 days of the experiment. We conclude that traditionally smoked trout has many advantages in terms of quality and safety of the products. Thus, the obtained products are safe for consumption for at least 30 days after processing. [ABSTRACT FROM AUTHOR]

Water quality parameters determines the success or the failure of a fish culture operation, so any proper-prepared plan for aquaculture must describe the quality and quantity of water available for this purpose. The aim of this study was to evaluate the physical and chemical water parameters in Rainbow trout culture, in the summer season from three salmonid farms, due to the environmental changes that are nowadays happening and affect the fish culture operation. The water samples were collected from Bistria-Năsăud County, from three trout farms: Strâmba, oimul de Jos and Fiad, in the summer of 2018, between May and August. For the determination of water parameters (dissolved oxygen, total dissolved solids, electrical conductivity and resistivity, pH, temperature, salinity) was used the Hanna HI 9828/4- 01 Multi-Parameter and for the chemical parameters (total ammonia, nitrates, nitrites) samples were transferred to the USAMV laboratories. The samples collection was made in each farm from three different places: catchment, basins and evacuation water areas. The results of the study showed that the parameters observed from the three farms were different, with major differences in month of July and August. The environment of fish aquaculture is a complex system with critical parameters as are the temperature, suspended solids, dissolved oxygen, nitrite and ammonia. However, the temperature and the dissolved oxygen are the most important parameter, requiring continuous monitoring in aquaculture production systems, due to the fish aerobic metabolism which requires an elevated level of dissolved oxygen at optimum temperatures. [ABSTRACT FROM AUTHOR]

The body temperatures of rainbow trout, Oncorhynchus mykiss were monitored from June through August 2018 in three trout farms from Bistrița-Năsăud County (Romania). The body temperature was measured from 3 different regions of the body: head, trunk (epaxial and hypaxial muscle region) and caudal peduncle. Body temperatures were compared to the basins water temperature. The lowest water temperature in the basins was recorded in May and June, in Șoimul de Jos farm, and the highest temperature in Fiad farm. In July, Strâmba farm, recorded the highest water temperature, and in August, Fiad farm. In all farms studied, the body temperature of the trout was higher than that of the basins water temperature regardless of the studied region. The highest differences between the basins water and body temperature in farms were found in the caudal peduncle and epaxial muscle regions, due to their role in locomotor mechanism. This is due to the high growth density, the feeding and the intensification of metabolism, with energy release, as well as a much higher level of stress than that encountered in the natural environment. [ABSTRACT FROM AUTHOR]

The parameters studied were RBC, Ht, Hb, erythrocyte index MCV, MCH, MCHC, and oxidative stress through SOD and GPx. For each parameter, blood samples were collected at specimens weighing between 100-140g in the summer season, 250-280 g in the fall, 270-300g in the winter and 320-350g in the spring. At the specimens studied the highest values of GPx and SOD were recorded in the spring season due to the stress caused by massive precipitation. During the study, the water temperature ranged between 5.1° C in winter and 19.2° C in summer and O2 ranged between 8.30 mg/l in the summer and 10.20 mg / l in winter. For most parameters, the highest values were recorded in the spring season and the lowest in the summer season. The data obtained in each season on Oncorhynchus mykiss species do not indicate pathological conditions but more an adaptive fish response to environmental conditions and can serve as a database for future research on welfare of salmonids. [ABSTRACT FROM AUTHOR]

Rainbow Trout (Oncorhynchus mykiss) breeding females have been studied from the standpoint of phenotypic characteristics and breeding indices for establishing future protocols of selection and improvement. The relative fecundation (RF) has been determined to a medium value of 335.88 ± 17.723 g and a variability coefficient of 52.77%. The high value of the variability coefficient is due to the fact that this is the first breeding generation of trout nursery and has not been submitted to any selection and improvement activities up to the present. From the breeding performance standpoint, the medium value of the number of eggs (TNE) obtained has been of 8127.44 ± 478.532, the medium egg weight (EW) has been of 0.06 ± 0.001g, the medium diameter of one egg (ED) = 4.16 ± 0.029 mm and the medium volume of one egg (EV) has been of 65.63 ± 1.223 mm3. The following breeding indices have also been calculated: gonadosomatic report (GR), Behning fertilizing coefficient (BFC) and the Williams absolute fecundity indices (WAFI). The outcome results have been the following: GR = 14.82 ± 0.587; BFC = 16.82 ± 0.563; WAFI = 5.77 ± 0.333. The values of the correlations point out the necessity of breeding selection work in order to improve the breeding performances. [ABSTRACT FROM AUTHOR]

Prior knowledge about correlation coefficients between major somatic characteristics can be used to guide breeding programmes in aquaculture. The purpose of our research was to characterize the Rainbow Trout (Oncorhynchus mykiss) breeders from a phenotypical standpoint and to test the existence of correlations that can be used in future research studies. Somatic and gravimetric measurements have been performed on 3-year old females and males, obtained and raised in a regional fishery. Significant difference (646.11 g; p<0.05) was obtained between the mean values of body weight (Bw) in females (2208.38±37.48 g) and in males (1562.27±74.113g). In terms of total length (Tl), significant differences were recorded also between mean values, in favour of females (53.01±0.271 cm) as compared to males (46.65±0.742 cm). The difference between average values of standard length (SI) was (6.86 cm) statistically distinctly significant (p<0.01), in favour of females (42.57±0.682 cm in males; 49.43±0.259 cm in females) and also for the commercial length (CI) in the same sense (d=5.92 cm). For the other conformation features studied (maximum height - MH, minimum height - Mh, body depth - Bd, head length - Hl and caudal peduncle length - CpL), the recorded differences between males and females were statistically insignificant (p>0.05). The outcome values reflect a higher interdependence between some studied characteristics in males, as compared to females, as indicated by Pearson’s correlation coefficients and open the direction in which the real selection can be done. [ABSTRACT FROM AUTHOR]

Given that the market demand for food is growing, aspect correlated with climatic changes more pronounced in the last decade, the growth technologies in fish farms it adapt, trying as much as possible to exclude environmental factors from the production equation. This is possible by maintaining constant physicochemical characteristics of water, artificially, using recirculating systems. Because some of the most important stages of the technological growth of trout are incubation, hatching and post-embryonic development, in this study we want to evaluate the obtained performance in two different growth systems: a classical system for incubation and post-embryonic development, respectively a recirculating system. Taken in the study two groups of 10.000 trout eggs each, with common origins, were studied and monitored: physico-chemical characteristics of the water in the two systems, losses during incubation, hatching rate, survival rate, duration of incubation and growth dynamics during post-embryonic stage. The results showed favorable and approximately constant values of the physico-chemical parameters in recirculating water system, while in the classical system were major variations. Also, the results for the other proposed objectives were favorable for the exploited group in recirculating system. This reflects the importance of recirculating systems using, at least in the early stages of the technological process. [ABSTRACT FROM AUTHOR]

Starting from the premise that achieving higher production and economic performance in the salmonid farms is strongly influenced by the processes of artificial breeding, on this study we wanted to highlight the optimal age at which rainbow trout (Oncorhynchus mykiss) females can be used for breeding. For this, where randomly selected from the each growth basins, 20-breeding females by the following age groups: 3, 4, 6, 8 and 10 years. Were determined: body weight of each females, the total number of eggs / female, individual mass of eggs, the diameter of eggs, the volume of eggs, respectively the individual weight of the ovaries. Based on the obtained data, were calculated the following selection and breeding indices: gonado-somatic report (GSr), Behning fertility coefficient (Bfc), respectively Williams absolute individual fecundity index (Waif). In the gonado-somatic report (GSr) was found an increased value from 15.33 ±0.299 at 3 years age, up to a maximum of 17.194±0.366 (at the age of 6 years). For females of 8 and 10 years ages, its found an decreased value from this report (16.267±0.406, respectively 13.070±0.630). For the Williams absolute individual fecundity index (Waif), were obtained increasing values, proportional with age (4.278±0.279 at 3 years, 6.799±0.562 at 10 years). The same aspect has been reported in the case of Behning fertility coefficient (Bfc). Based on evolution of selection and breeding indices values, we recommended in the technological processes the use of rainbow trout females with age between 4 and 8 years. [ABSTRACT FROM AUTHOR]

Consumer preferences regarding the various species of fish or aquatic organisms are highly variable. The criteria by which they orient are represented by: the price, organoleptic characteristics, healing and nutritional properties of meat. Today it is known that a high consumption of fish meat has a beneficial role in human health. Moreover, statistics indicates a high level of life expectancy in countries with tradition in terms of fish consumption, e.g. North- European and Asian countries. Statistics shows a high consumption of ocean fish and different species of salmonid family. The culture and intensive fish farming represents an alternative to the requirements of the fish market. The salmonids farmers focus their efforts to obtain high yields of high quality, in conditions of maximum economic efficiency. In Romania, the predominant specie encountered in salmonis farms is rainbow trout (Oncorhynchus mykiss). It is successfully reared because of its plasticity and resistance to changes in environmental conditions and disease, and efficient feed-conversion. For restocking mountain water with biological material, some trout farms operate successfully brown trout (Salmo trutta fario), a less effective specie for meat production, due to slow growth and development and low resistance to changing environmental factors. Profitability of fish production depends on the propagation processes, fish growth and developments, and supplying optimal environmental conditions for enhancement of the biological potential. The artificial reproduction of salmonids, involves several technological operations for achieving outstanding results on fisheries production. Of these operations, critical is the selection and improvement of breeding. [ABSTRACT FROM AUTHOR]

Clinical and paraclinical investigations (morpho-pathologic, bacterioscopic, bacteriologic and sensitiveness test to antibodies) done on 20 fish (rainbow trout), dead or in agony state, taken from a furunculosis pesthole in Salmonidae and proceeded from an intensive exploitation unit of trout, in Cluj county, put in evidence the following aspects :To clinical exam, in breeding basins, it appears individuals (5 %) which have presented locomotor troubles, listless and untidy swimming in water surface, lateral swimming anorexia, and on tegument it is observed diffuse hemorrhagic zones, lost of fish scale and necrosis of fins. It appears also secondary infections with fungi of Saprolegnia genus under the form of a white- dirty, downy film. From the 20 trut corpses were isolated 2 bacterial strains, from anterior kidney and from raclage in fin basis, with congestive lesions. Bacteria isolated are developing only after an incubation at 20 - 25° C and does not grow up to 37° C, and to microscopic exam directly from sauce, the mobility is absent Classic biochemical tests put in evidence the following positive biochemic properties: cataloze, oxidaze, indolal and the presence of hemolytic activity. Biochemical properties testing on API20E gallery also puts in evidence properties as : positive gelatinousis and sucraze fermentation. Based on bacterial strains development isolated only to 20 - 25 °C and the above mentioned biochemic properties, respectively the absence of pigment, bacterial strains isolated are appointed in Aeromonas genus, Aeromonas salmonicida species, achromogenes subspecies. By sensitiveness test in different medicine substances, using antibiogram technique, bacterial strains isolated from pesthole are sensitive in a decreasing order to: nalidixic acid, oxitetracycline, florfenicol and eurofloxacin and resistant to ampicyline, amoxiclav and colistin. [ABSTRACT FROM AUTHOR]

Growth dynamics of rainbow trout (Oncorhynchus mykiss), superior to other salmonids species, led to the exploitation of this species in the most countries of the world. The individuals of this species, depend on many factors, like environment, nutrition and genetics. In this study, authors have followed over 540 days, the evolution of body mass and average daily gain at the specimens of rainbow trout from Fiad-Telcisor salmonids complex, Bistrita-Nasaud county, from the larval stage and up to the stage of trout for consumption with an average weight of 250 gr. These studies are necessary to prepare a strategy on fisheries production planning, depending on market demand of these products and eliminating additional costs due to over production. Fish and fish products always represented a staple food in human nutrition. The aquatic resources of continental and oceanic natural waters, have permanently assured the humanity's food needs, but today, on the conditions of the demographic boom, may be destroyed the ecosystems balance, on the strenght of irrational exploitation of their (Svennevig & co., 2000). For this reason, specialists' attention bound for aquaculture, field of the last years a real progress (Goldburg & Naylor, 2005). On this economic stage, a fierce commercial competition and significantly reduction of the market price, involving development and alignment a new concept of strategy, to decrease the production price. For this, aquaculture producers focus their efforts to obtain high yields at a high quality level and in conditions of maximum efficiency. A common situation on the fish market in Romania, is to sell products. Lack of strategy on the relationship between production capacity of fish farms and marketing opportunities of these products, lead to the accumulation of hardly marketable stocks which involving additional financial burden (Popescu, 2009). To avoid such situations, are requested market studies and research on the possibilities to obtain rhytmic and constant productions. They involve serious knowledge about factors which influence the physiology of fish growth (Cocan & co., 2009). In Romania, but also in many other countries around the world, salmonid species predominantly found in farms are rainbow trouts (Oncorhynchus mykiss). It is successfully exploited, due to its plasticity and resistance to changes in environmental conditions and diseases, and due to efficient conversion of feed (Cocan, 2008). There have been numerous studies on the factors that influence the growth of rainbow trout, including: growth density, environmental conditions, water quality, the rate of removal of water or operating system adopted (North & co., 2006; Roque d'Orbcastel & co., 2009; Sørensen & co., 2005; Matthews & co., 1997; Clark, 2003). Leatherland (1993), has conducted studies on interaction between plasma growth hormone, thyroid hormones and cortisol concentrations in rainbow trout, depending on the density of growth (150 kg/m³, respectively 60 kg/m³). The results demonstrated that to a high density, the growth rate drops significantly, due to high concentration of cortisol, but also due to restricted diet because of the high density. Because are poikilotherms, trouts shows changes of behavior and some physiological parameters according to season (Gallardo, 1997). Temperature is one of the abiotic factors with a major influence on the development of metabolic processes. Farming system adopted are also greatly influence on the growth dynamics of rainbow trout, each showing the advantages and disadvantages. Recirculating systems (RAS) providing optimal growth conditions, medial parameters being monitored continuously (Sirakov & Ivancheva, 2008), but inefficient water filtration systems can affect meat quality (Rønsholdt & McLean, 1999), or may give rise to health problems (Svobodova & co., 2005). Classical breeding systems are often at risk of contamination by polluted waters (Moogonei & co., 2010), and environmental conditions can not be controlled. In this study, authors have monitored the growth dynamics, body mass evolution and average daily growth of rainbow trout (Oncorhynchus mykiss), from Fiad-Telci or salmond complex. [ABSTRACT FROM AUTHOR]

Fish and fish products were always a commodity in human nutrition. Aquaculture resources of natural continental or maritime waters permanently secured human food needs, but today, under the global population explosion, humanity may destroy the balance of existing ecosystems by exploiting their irrational considerations to which attention is directed to aquaculture specialists, knowing that real progress in recent years. In this economic stage, a fierce commercial competition and significantly reduce the market price, and achieving alignment implies a new concept of strategy to lower production cost, which ends with the use of improved genetic lines. Genetic improvement programs correctly applied in accordance with existing species and environmental conditions will help increase the performance of production and reproduction of fish and getting a low production cost, benefiting in this respect, both producers and consumers. [ABSTRACT FROM AUTHOR]

Statistical data of last years reveal a significant fish consumption increase by human, but also of other aquatic organisms, which are over 400 species, from which fishes represent about 200 species. Because natural resources are more and more reduced, the aquaculture has an ascendant trend and inside it the salinoniculture detains a forehead place. in this context, it is necessary to be permanently perfected salmonid breeding methods and technologies, following to obtain some production qualitatively as great and appropriate as possible, by maximum exploitation of the biological potential of culture material. inside this experiment, the authors determined the body weight and main morpho- physiological indices on a number of 40 rainbow trout (Oncorhynchus mykiss) breeding stock individuals, taking in study randomly 10 individuals (5 males and 5 females) from the existent four breeding stock populations inside Fiad trout farm, Bistriţa-Năsăud County. Description of these body weight indices and those of body frame ones, on age categories, will permit inside this trout farm the optimal age, body weight and body frame determination that breeding stock must have in view to obtain some viable and valuable offspring, both qualitatively and also quantitatively. Finally, the obtained data were statistically processed and interpreted. [ABSTRACT FROM AUTHOR]

Simple Summary: Rainbow trout is one of the main freshwater fish species farmed in Romania, in a temperate continental climate. Blood biochemistry parameter values are well known for humans and other higher vertebrates, including some species of fish, and are fundamental for the assessment of physiological status. In this study, we examined the physicochemical parameters of water quality and the blood profile (hematological and hormonal profiles, antioxidant enzyme activities) of rainbow trout females reared in three farms, during the summer season, to monitor stress. These findings permit the progress of knowledge of blood parameters in fish and will encourage efforts to expand hematological and biochemical studies to assess the health of salmonids, which is essential for the sustainable development of aquaculture. Blood biochemistry parameters are valuable tools for monitoring fish health. Their baseline values are still undefined for a multitude of farmed fish species. In this study, changes in the blood profile of rainbow trout females (Oncorhynchus mykiss) from three farms were investigated using different biomarkers during the summer season. In the given context, the main water physicochemical parameters were investigated and twelve biochemical parameters were measured from blood samples of rainbow trout reared in the Fiad, Șoimul de Jos, and Strâmba farms. We selected these farms because the genetic background of the rainbow trout is the same, with all studied specimens coming from the Fiad farm, which has an incubation station. Forty-five samples were collected monthly (May to August) throughout summer to observe the changes in the blood profile of rainbow trout. Principal component analysis showed a clear separation both among the studied farms and months. Furthermore, significant correlations (p < 0.05) between the majority of the biochemical parameters were found, indicating that the environmental parameters can influence several blood parameters at the same time. The present study provides several useful norms for assessing the welfare of rainbow trout, indicating that the relationships among different parameters are important factors in interpreting the blood biochemical profiles. [ABSTRACT FROM AUTHOR]

In the context of increase the fish farms productivity and diversification of aquaculture products, have been evaluated the growth dynamics of three species of trout: rainbow trout (Oncorhynchus mykiss), brook trout (Salvelinus fontinalis) and arctic charr (Salvelinus alpinus). All three species of trout were grown in Trecătoarea Ursului trout farm, Braşov County and have benefited from the same environmental parameters and the same feeding conditions. The growth dynamics of rainbow trout was significantly higher, compared to the other two species. This is the result of domestication and improvement of rainbow trout, as well as its genetic characters. The lower growth dynamics of brook trout and arctic charr increase the production price, this aspect having directly implications on the selling price. [ABSTRACT FROM AUTHOR]

It was examined the influence of seasons and farming systems on hematological profile of rainbow trout (Oncorhynchus mykiss). In the classical growth system, the mean values of hematological indices showed large variations, depending on the season. In the recirculating growth system, hematological indices were relatively constant, regardless of the season. [ABSTRACT FROM AUTHOR]

Because recirculating systems for breeding fish (in general) and trout (in particular), are more and more used in fish production and aquaculture, we investigated the influence of two different growth systems (classic system vs. recirculating system) on the fish health. Physiological status of trout was evaluated by histological investigations made at the liver level. At trout reared in the classical system, histological changes have not been major. At trout reared in a recirculating system, where environmental conditions are maintained at optimum parameters, voluntary feed intake (much enhanced by optimal environmental conditions), led to the appearance of massive lipid inclusion, such as the liver appears to be a hypertrophic fat mass. This may lead to the occurrence of the diseases and could endanger fish production. [ABSTRACT FROM AUTHOR]

Due to modernization of growth technologies and the increasing of growth trout densities, were highlighted differences in terms of the final products obtained quality. Therefore, we aimed to identify the possible morphological and histological changes of the digestive system of rainbow trout, by adequate investigation on some specimens from two different farming systems, one classical and the other superintensive-recirculating. Respecting the working protocols, were slaughtered trout from each system, being prelevated samples and segments of the esophagus and stomach. The results did not reveal morphological and histological differences, except for some lipids deposits. [ABSTRACT FROM AUTHOR]

Because there are few salmonid farms in Romania where trout are artificially breed, is necessary for them to streamline their technological and economic activities, based on a selection-breeding program. Factors that influence the production and reproduction performance of rainbow trout are numerous, one of them being breeding age. Due to this, we aimed to identify the optimal age for use in breeding females of rainbow trout. For this, were randomized retained 20 rainbow trout females with 3, 4, 6, 8 and 10 years age old (20 from each category). They were weighed and measured, being analyzed the breeding performance, like ovary weight, the total number of eggs, egg diameter, egg volume, individual mass of eggs. The obtained data were used to calculate the reproduction indices: gonadosomatic ratio GSr, absolute individual index of fertility - Williams Waif, Behning-fertility coefficient Bfc. Between the values of these indices and the values of initial phenotypic characters analyzed, were calculated correlations. The results lead to the conclusion that, in practice, must be used rainbow trout females between the ages of 4 and 6 years. [ABSTRACT FROM AUTHOR]

Reproduction is one of the most important function of organisms, after which arise descendants that inherit the parental characteristics. At fish, the reproduction is materialized following the occurrence a large number of gametes (Miclea and Zăhan, 2006). At the majority salmonids species, the breeders are procured from the natural environment, during the breeding. In rainbow trout (Oncorhynchus mykiss) case, the breeding stock is reared in special ponds from the trout farms. In this case, the breeding stock is the results of a strict selection (Gjedrem, 2005), and the growth requires optimal environmental conditions. As the literature shows differences regarding the production performances of rainbow trout female according to their age (Fornshell, 2002), in the present study we aimed to determine the fertility and eggs quality in four age categories. [ABSTRACT FROM AUTHOR]

The article presents a summary of a study on the peculiarities of oro-pharyngeal cavity of rainbow trout fish. It shows that the oro-pharyngeal cavity, which represents the first section of the digestive tract in fish, has some morpho-histological peculiarities in terms of shape and of couple anatomical segments. It also characterizes the morphological and histological attributes of the said segment of the fish's digestive system.

Fish meat is an important source of nutrients, having organoleptic and dietary properties, especially important for human nutrition, in the form of essential and non-essential amino acids, and unsaturated fatty acids such as Omega 3, Omega 6, Omega 9 and Omega 12. They are essential for preventing and treating cardiovascular disease or various forms of cancer, like colorectal cancer. In the present study, characteristics and chemical properties of the meat were analyzed in eight different fish species: rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix), European sea bass (Dicentrarchus labrax), golden grey mullet (Liza aurata), mackerel (Scomber scombrus), sea bream (Sparus aurata) and prussian carp (Carassius gibelio). The characteristics and chemical properties of the meat were analyzed, taking into account the anatomical muscle segments (epaxial muscles, hypaxial muscles and caudal peduncle muscles). The analyses of the chemical composition of the meat consisted of: water content (%), dry matter (%), crude protein (Pb%), crude fat (Gb%) and mineral content (Min.%). The proximate analysis results are influenced by many factors, such as the sex of fish, the age of fish, the catch season, the farming system used, the geographical region of catch, the time from harvest to analysis, the conservation method, and many others. The results offer important information regarding the structure and composition of fish meat available on the market. [ABSTRACT FROM AUTHOR]