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Following-up organic pollutants in the course of producing foods
244-248Views:391We analysed the raw materials in various food products, including additives, carrier solvents and end product for several selected organic pollutants. We analysed these food products for the type of chlorinated hydrocarbon pesticides, polychlorinated biphenyls and other currently used pesticides.
We analysed three product categories: bakery products, canned mushroom and meat products. The analysis of the bakery products and of the canned mushroom did not conclude in positive findings, which means that these products contained the agents given during the production of the product and the environmental pollutants in undetectable low concentration.
However, the results for meat and fish products indicate that polychlorinated compounds are persistent and are of a lipophyl character, as some of these components have been detected in these food products, the concentration of the PCBs were detected in the range of 9.8-24 μg/kg. -
The effects of bioactive feed additives for the production parameters of common carp (Cyprinus carpio) fingerlings in intensive recirculating system
35-41Views:388For the appropriate quantity and quality of fish meat the pond farmers need to use up to date nutrition and feeding technologies. Recently the intensification of the carp production is stepping up with the availability the proper quality of the artificial feeds. The using of different feed additives make a better feed conservation ratio, faster growing rates and more uniform stocks.
In our experiment what is made with common carp (duration of the experiment was 8 weeks long) we compared two different kinds of feed additives in different doses. One of them contains only natural mineral elements and the other additive is a natural origin probiotics. Both additives were used in the quantity of 0.5, 1 and 2% of the total feed. By the result of the 8 weeks experiment it could be said, that the using of the humic acid based mineral elements feed additive. Makes a better FCR comparing with the control stock, but was not as good as the using of the probiotics. At the humic acid treatments the more doses, the better FCR value, but at the probiotics it wasn’t true. The 0.5% probiotic treatment gave the best result. It is concluded that the using of the probiotic feed additives always gave a better performance of the fishes (average weight, biomass, FCR) than the humic acid treatments. The using of the feed additives hasn’t got an influence for the survival rate of the carps.
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Fishes protected of Natura 2000 system in Slovakia
9-12Views:128The timely and effective establishment of Natura 2000 network is one of the greatest environmental challenges for the new Member States of the European Union. Slovak Republic is facing this challenge now. By the June 2005, the Government in our country must prepare a list of sites to be included in the Natura network, according to the criteria set up in the Habitat Directive. Natura 2000 sites, according to the specificEUDirectivesconsistofSpecialAreasofConservation(SACs),andSpecialProtectionAreas(SPAs).TheSPAsandtheSACs, the latter selected as Sites of Community Importance (SCIs), will be incorporated into the Natura 2000 network. The problems of proclaiming the system of protected areas of European importance for the Natura 2000 have been one of the major topics of the ichthyological activities in our country in recent years.
For 3 lampreys and 20 fishspeciestheterritoryofpotentialsiteofcommunityinterest(pSCI)hasbeenlimitedandproposed.Theselection of localities and examinations of population state in individual species of fishespresentedintheAnnex(II.,IVandV.)totheCouncilDirective No. 92/43/EEC were carried out in 2003/2004. In total 179 pSCI localities for fishandlampreysinthealpinebiogeographicregion (83) and in the pannonian biogeographic region (96) pSCI in the Slovak republic were selected and limited. The number of pSCI localities selected for individual species is different regards to their distribution within the river net of Slovakia. For example, for species of general distribution, 30 localities pSCI (Misgurnus fossilis, Rhodeus sericeus, Gobio albipinnatus, Barbus barbus) or 35 localities pSCI (Cobitis elongatoides, Barbus peloponnesius), have been proposed, on the contrary, in several species of exclusive distribution as Lampetra planeri - 8, Gobio uranoscopus - 9 and Zingel zingel -12 localities.
The pSCI territory for individual species of the ichthyofauna presented here represents the firststageintheprocessofcreatingtheprotected territory system of European interest Natura 2000 in the territory of the Slovakia for this group of aquatic vertebrates. The list of proposal sites will have to be submitted to the European Commission by the date of Accession. -
Comparative study of wold and lowland situated small watercourses from fishbiological aspect
54-59Views:120Fishbiological research was held on 10 small watercourses, especially on the streams of woldy region of the southern foot of the Bükk-mountains and on the creeks of the lowland Borsodi-Mezőség in 2004. 7475 specimens of 34 species were caught as the result of our surveys on 28 sampling sites. Significant differences were found between fish stocks living in wold and lowland situated sampling sites.Nevertheless on the border of the hilly and lowland regions continous transition observed in the composition of fishstocks. Using Ind Val 2.0 statistical software indicator species appointed of the stocks of wold situated samling sites in “natural” and in “disturbed” states, and of the lowland situated sampling sites.
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Effect of different n-6/n-3 fatty acid proportion oil sources on reproduction performance and fatty acid profile of milk in modern genotype sows - Pleminary results: Preliminary results
121-128Views:266This study was conducted to investigate the effects of supplemental n-6 and n-3 fatty acids on sow’s milk fatty acid composition during the lactation period and on reproductive efficiency of sows in the subsequent gestation period. Data were collected on a total of 213 DanBred sows (108 control and 105 experimental) representing parity of 2–7, respectively. Control and experimental sows were placed in the same housing conditions during lactation and gestation period. Control group received 6.3 g of sunflower oil (SO) per kg feed as n-6 fatty acid supplementation, whilst experimental animals received the same amount of fish oil (FO) as n-3 fatty acid source. Diets were corn meal-extracted soybean meal based. The experiment was conducted in one replication as being a part of a longer and more comprehensive trial. It was found that the consumed long-chain polyunsaturated fatty acids (LC-PUFAs) appeared in the sow’s milk and changed its fatty acid profile. With this alteration, the n-6/n-3 ratio of experimental (FO) sows’ milk were narrower than in SO group (SO: 13.82 vs. FO: 5.89). The benefits of n-3 fatty acids supplementation were evident for the subsequent reproduction cycle, when experimental sows heated more reliable and earlier than control (weaning to oestrus interval: SO: 5.86 vs. FO: 4.48 days). Only 2.33% of experimental sows (FO) did not heat within 7 days after weaning, but this was 12.36% in the control group (SO). The present study requires further research to evaluate the effect of n-3 fatty acids on maintenance of pregnancy and improved subsequent litter size.
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Preliminary results of intraspecific sterlet hybrid (Siberian sterlet × sterlet) rearing under intensive conditions
17-19Views:208Due to early maturation and a small size, sterlet (Acipenserrut-henus) is a very advantageous fish for intensive sturgeon farming with regard to caviar production. According to our previous observations, the growth potential of Siberian sterlet (A.ruthenusmarsiglii) is higher than that of the European one. In our experiment, sterlet and an intraspecific hybrid (Siberian sterlet × sterlet) were tested under intensive tank conditions. During the 8 weeks of the experiment, survival, growth and size heterogeneity were investigated. According to the results, there were no significant differences in survival and growth but the size heterogeneity was higher in the hybrid. It is supposed that, in our trial, the applied water temperature range (24.0–25.5 °C) was optimal for sterlet, but was probably above the optimal range for the hybrid.
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The comparison of sperm motility and density in four different goldfish (Carassius auratus) types
135-140Views:292Different goldfish types play an important role both in ornamental fish farming and science. Considering its historical background, the goldfish is a suitable model animal for the study of artificial selection as well as for developmental biological studies. Sperm motility and cell density is an important parameter in determining sperm quality. The aim of our study was to examine the effects of different goldfish types on the sperm quality. Several sperm motility parameters (progressive motility (pMOT, %), straight line velocity (VSL, μm s-1), curvilinear velocity (VCL, μm s-1), linearity (LIN, %), amplitude lateral Head Displacement (ALH, μm), Beat Cross Frequency (BCF, Hz)) of four different goldfish types (Common goldfish-“wild type” N=5, Shubunkin N=4, Black Moor N=4, Oranda N=5) was compared during 60 hours (at 12-hour intervals) at refrigerated storage (4 °C). The variability of sperm density was also investigated in all types. A similar cell concentration was determined in the four goldfish variants (Common goldfish 2.01*1010 ± 3.46*109; Shubunkin 1.71*1010 ± 3.25*109; Black Moor 1.66*1010 ± 3.02*109; Oranda 1.56*1010 ± 5.83*109). Statistically significant difference between the 4 goldfish types in the motility parameters and cell density was not noted. However, a decreasing tendency in Black Moor sperm motility parameters (pMOT, VCL and VSL) was observable, as well as a reduced spermatozoa density in Oranda was also recorded. Our results can contribute to the improvement of the common hatchery propagation of goldfish. Future studies can add more evidence of the possible effects of artificial selection on the reproduction in different goldfish types.
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Survey of the environmental impacts of pond fish farming
19-24Views:176The aim of this study was to survey the nitrogen, phosphorus and organic matter loads and the discharge of fishponds. The inputs and outputs of nutrient amounts of fishponds and their sources are described. The impact of a fishpond on the nutrient loads of receiver waters was determined. The investigations of this study were to determine and evaluate the nitrogen, phosphorus and organic matter budget of fishponds representing different technologies and areas.
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A gombatermesztés szerepe az átalakuló magyar mezőgazdaságban
15-22Views:145The structure of Hungarian agriculture should be changed before the EU accession. The new structure should fulfill EU requirements and also produce competitive products. Unconventional products (mushroom, fish, honey etc.) have a lot of advantages: they can be produced on small farms, their trade is mainly free of regulation and their markets are almost unlimited. This paper deals with one of these alternative agricultural enterprises, namely mushroom production. Hungarian mushroom production – in spite of difficulties – has witnessed remarkable expansion: it has increased its production by fourfold and its export by fivefold in less than ten years. The low level of wages gives Hungary significant advantage over its competitors. If we could ensure the appropriate infrastructure (technical advice, bank loans, etc.) the mushroom industry would become one of the most profitable sectors of Hungarian agriculture.
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Data to the growth of yoy (0+) tenches (Tinca tinca L.) in Tisza Lake
102-105Views:186Young of the year (YOY) tenches (Tinca tinca L.) were caught in relatively great number in Tisza-Lake at the Tiszafüred section on last days of October in 2004. The standard length of these fishes varied between 20 and 46 mm. It seemed that the collected sample could provide appropriate data to examine the size-structure of YOY tenches, so we measured their standard body-lengths in mm and -weights in hundred parts of gramm unit. After the statistical analysis were found the follows:
1. The curve of length frequency corresponds with normal distribution, i.e. there was not found multimodal curve as could be expected in the case of a periodic spawning species.
2. The average standard length of the examined individuals – although the environmental conditions of the population is good – was only 31 mm. It is far below the 37 mm average of the lowest growth of tench population was found in the scientificpapers.
3. More than 20% of measured sample belonged to the range of 20-26 mm. The estimated ages of these fish specimens are about 70 days, according the scientificpapers.
By right of above mentioned can be concluded that the sample represents only one age-group from a late spawning, and not the whole range of YOY tenches, so these data can give information about the size structure only of this group. The 31 mm average standard length of individuals, origin from spawning in late July or beginning of August is accordance with age and environmental conditions as well. -
The system of faunacomponents conception and its application to qualify the degree of naturalness of fish assemblages
93-101Views:151The increase of species richness in communities of natural biogeographic regions in an anthropogenic way can be expressed as biogeographic pollution. Where there is contaminated fauna, one must investigate how this occured. I studied how the members of Hungarian fishfauna could be present resident and have managed to workout a so-called system of fauna component conception which is suitable for this requirement.
The expression of ’faunacomponent’ includes other expressions. That kind of species belong to a certain faunacomponent that reached the studied area in the same way. Species reached the studied area without an anthropogenious contribution are qualified as native fauna components. These kind of species are endemic species, occasional species and settlers. In contrast to native faunacomponents, some kind of human influence is always detectable in connection with the way reached the studied area by non-native species. Accordingly, group of non-native species includes directly or indirectly facilitated settlers, species that are introduced accidentally and those introduced intentionally. It is obvious that classifying a given species could be construed solely in connection with a certain area.
Applying Shannon diversity index I have initiated the assemblage natural index (ANI) in order to show a way how to use the system of faunacomponent conception in practice. ANI refers to the degree of naturalness of faunistical samples. If ANI > 1 it means there are not any non-native species and ANI < 1 it means there are some non-native species in the sample respectively. In the latter case ANI decreases proportionally with the number of non-native species and specimens. In that special case when only one specimen of only one non-native species can be found in the faunistical sample ANI = 1. -
Managing the relationship between natural spawning areas on unprotected floodplains and on protected man-made fishponds
25-31Views:156The economic land management of unprotected floodplain areas is possible only if considered jointly with protected floodplain areas, for which facility fisheries provide a solution. One solution could be that a part of the natural fish increment of the spawning-grounds on unprotected floodplains be raised in protected side fishponds and then later sold. This kind of fishery utilization is also favourable from economic, conservationist and flood protection aspects.