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Results of Brown Bullhead Fingerling Rearing in Recirculating Fish Production Systems
46-50Views:90Predator fish species are in great demand, both in fish production and consumption. Because of their rarity and perfect meat quality, these species have considerable economical significance and increasing domestic and foreign demand.
The brown bullhead (Ictalurus nebulosus) has been in Hungary for more than 100 years, but not popular because of its early maturation rate, aggressive reproduction and slow growth. Despite of these properties, larger specimens (about 150-200 g) are marketable overseas.
Our objective is to ensure the adequacy of the brown bullhead in intensive fish farming and its biological, technological and economic references. The pre-experiments were performed at the Bocskai Fishing Co-operative in Hajdúszoboszló, where we reared the juvenile age class. In our university’s recirculating system we examinated the brown bullhead from the fingerling age class.
The black bullhead prefers artificial feed, and produces excellent growth parameters and a specific feed-live weight conversation ratio. -
75 years of the chestnut blight fungus Cryphonectria parasitica (Murr.) Barr in Europe
82-85Views:171The chestnut blight fungus Cryphonectria parasitica is a native pathogen in East Asia and has been introduced into North America and Europe. Historical records and population genetic studies revealed at least three major introduction events from Asia into Europe.
Nowadays, chestnut blight is present in almost the entire distribution range of European chestnut, i.e. from the Iberian Peninsula to the Caucasus. The C. parasitica population in most countries has been studied in respect to the diversity of vegetative compatibility (vc) types and the occurrence of hypovirulence. The vc type diversity of the different populations varied considerably. Typically, a high diversity of vc types has been found in areas with a long history of chestnut blight and where sexual recombination between divergent genotypes commonly has occurred. On the other hand, newly established populations often showed a low diversity with only one, or a few vc types present.
Hypovirulence, i.e. the occurrence of C. parasitica isolates infected by Cryphonectria hypovirus 1 has been found widespread in Europe. Natural dissemination and active biological control applications have lead to a high prevalence of the hypovirus and to the recovery of many chestnut stands. Virulent cankers became hypovirus-infected within a short time and ceased expansion. There is concern that the diversity of vegetative compatibility types could increase in Europe through sexual reproduction between C. parasitica genotypes originating from different introductions. A higher level of vegetative incompatibility would not only hamper hypovirus spread within a population but could also select for lower virulence in CHV-1 and subsequently lead to an erosion of biological control. Recent studies, however, indicate that the vc type barriers are not so restrictive than previously assumed and that so far no evidence for an erosion of biological control system in high diversity populations can be observed.
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Complex assessment of inland water fish stocks
74-80Views:70In the domestic fish production, natural waters have yielded for several years about 7-8 thousand tons. This, from the point of view of outputs, considering the almost 130 thousand hectares of natural water, is rather low, it means approximately 55-60 kg/ha mixed fish.Although the various natural waters can differ significantly on the basis of yields, yet on the majority of the territories, the results were low. In the case of our extensive still waters and rivers, the reason can undoubtedly be found in the combined effect of the lack of the possibility of reproduction of the fish stock and the over-fishing. Fishery built on planning supposes the best possible knowledge in the given circum stances of the parameters of the water area and its fishstock. Lacking this knowledge, it is not possible to establish the optimal use fulness of the resources, what is more, the management can make faulty decisions – as a result of a lack of information -, which can risk the success of later activities.
It is known that many factors have an impact on the success of the fishery, as well as some information in connection with the water area and the fish stock are necessary, the knowledge of which make it possible to manage the fishery in a planned way. One part of the information is available, while the other part is incomplete or not deep enough. The necessary data are dissimilar depending on their nature, can be obtained from different places, by different methods.
As the first step for executing the field surveys and processing data, I developed a complex model, which contains in a unified system the steps of estimating the fishstock. I made the sampling on the basis of this. Part of the model is a fish faunistic survey, as well as a morphological survey of the water area. The information gained from these are important for making more accurate the system of devices of the samplings for stock estimation (duration, number of net-rows) and for assigning its place (places representing the best way the physical characteristics of the given water area). The major stages of stock-survey: A) faunistic survey, B) physical survey of the bed, and C) sampling with the help of gill-nets. This is followed by the evaluation by the computer module.
The results of the research create a methodological and technical background for the fish faunistic and population biologic surveys still performed in different ways in our country, and by applying these methods together, all basic information about natural waters which help decision-making concerning fisheries can be obtaine deffectively. -
The effect of wet compost extract on the root tubers of green pea
51-54Views:134Nitrogen plays significant role in the life of plants, it could be the main limiting factor of plant growth. Sustainable plant nutrition pays attention to satisfy the plants’ nutrient demand without chemical fertilizers, e.g. by bounding the atmospheric nitrogen. The nitrogen fixing organizations play important role in supplying plants with nitrogenbecause the N2-fixingbacteria can fix high amounts of nitrogen.
Many effects of the sewage sludge compost extracts is known in the literature. We studied the effect of sewage sludge compost water extract in laboratory conditions on the growth of Rhizobium spp. isolated from green pea, while in a small plot experiment thepea-Rhizobium symbiosis were studied on sandy soil in the Nyírség region. The extract was produced under aerobic conditions. The compost extract was applied before and/or after sowing. In the laboratory experiments we used the sterile version of extract, in different doses.
In our work we present the effect of compost water extract on the number of green pea roots nodules, dry weight of the plant and reproduction of the Rhizobium bacteria. -
Polymorphism of the bovine GH and LEP genes in a population of Slovak spotted bulls
19-23Views:91The aim of this study was the detection of polymorphism in the bovine growth hormone and leptin genes using the PCR-RFLP method. A
polymorphic site of the growth hormone gene (Alul loci) that results in amino acid change at position 127 of the protein chain (leucine, L to
valine, V) has been linked to differences in circulating metabolites, metabolic hormones and to milk yield. The polymorphism in bovine leptin
gene is situated in the intron between two exons, which results in an amino acid change at position 2059 of the protein chain (cytosine, C to
thymine, T). The polymorphisms were studied in a group of 58 bulls of the Slovak spotted breed. A strategy employing PCR was used to amplify 428 bp (GH gene) and 422 bp (LEP gene) products from blood samples. Digestion of PCR products with restriction enzymes AluI and Sau3AI revealed alleles: L and V; A and B for GH gene and LEP gene, respectively. The growth hormone gene is a candidate gene for body weight gain in cattle, since it plays a fundamental role in growth regulation. Leptin plays an important role in the regulation of feed intake, energy metabolism, growth and reproduction of cattle; therefore, animals with higher leptin gene expression will probably have lower daily weight gain than others with similar forage offer and nutritional condition and will also likely have longer calving intervals. -
Usability of vegetable extracts in the protection against Alternaria alternata
113-116Views:132In our country, wormwood ragweed (Ambrosia artemisiifolia) may cause serious problems. Nearly 5 million hectares of agricultural area was infected with ragweed (Ambrosia artemisiifolia), which is believed useless weed. Allergological point of view, most problematic weeds adventive. However, many physiologically very beneficial compound also included, those with the effects have been known also by the Indians. On this basis, herbs can be thought of as ragweed. Our goal was to present that the ragweed contains antifungal active substances as well. In this paper we tested the biological activity of the extracts against Alternaria alternata F.00750 in vitro. We related based on our examination that ragweed contains biologically active agents, by which it is hampered the reproduction of the Alternaria alternata. The minimum effective concentration was 300 mg extract in a Petri dish, which was three days inhibited the growth of fungus. Full fungicidal effect was observed over dose 525 mg.
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Clay-pit systems fishfaunistic research in the Middle-Tisza
81-92Views:70After the regulation of the Tisza River the chance of successful fish propagation lessened. Natural spooning places in the river almost completely disappeared. The fish have to find an adequate place for their propagation in the flood plain. The period of spooning usually coincides with flooding of the river. At this time fish try to find the flooded shallow places for spooning. These parts mostly include the clay-pits beside dams, which were accidentally established during construction of the dams. At this place the fry can find the necessary food. After decreasing the flood the fingerlings and a part of the spooners are trapped inclay-pits as these latter ones are not connected with the river bed. The clay-pits usually desiccate during the summer. The trapped fish population is eaten by water birds or harvested by the local man population. This means a great loss for reproduction of some fishspecies.
Within the framework of the Regional Rehabilitation Program at Nagykörű, supported by the “WWF Hungary” and a “SAPARD project,” these clay-pits became connected with each other in a stretch of 5 km, and they were jointed to the Tisza by a collecting channel. The water level has been regulated by a flood gate so that the water enters the holes during the flood and is released later on in to the water bed.
Data on fish were collected from the Nagykörű Whole System, from the Anyita pond and some isolated wholes in Szandaszöllős in 2004 and 2005. First of all fish fry and fingerling were collected and the success of spooning at these places was examined. Fry was harvested by a 60 x 80 cm sized lifting net of 2x3 mm mesh size. In other cases nets used by anglers for catching prey fishes was also used. Data were also collected from local fishermen who participated in saving the fry and fishing of Anyita pond.
Of the several thousand caught fish specimens 28 species were identified, and among them 5 protected and 5 economically important species was found. Protected fishes were as follow: gudgeon (Gobio gobio), bitterling (Rhodeus sericeus amarus), weather fish (Misgurnus fossilis), spined loach (Cobitis elongatoides) and tubenosed goby (Proterorhinus marmoratus). Among economically important fishessamples of asp (Aspius aspius), carp (Cyprinus carpio), wels (Silurus glanis), pike (Esox lucius) and pikeperch (Sander lucioperca) were -
Effects of water deficit on the growth and yield formation of maize (Zea mays L.)
143-148Views:149Maize (Zea mays L.) is the most important consuming cereal crop in the world after rice and wheat. This requires an understanding of various management practices as well as conditions that affect maize crop performance. Water deficit stress during crop production is one of the most serious threats to crop production in most parts of the world and drought stress or water deficit is an inevitable and recurring feature of global agriculture and it is against this background that field study of crops response to water deficit is very important to crop producer and researchers to maximize yield and improve crop production in this era of unpredicted climatic changes the world over.
A pot experiment was carried out to determine the effects of water deficit on growth and yield formation of maize. Two maize cultivars were used Xundan20 and Zhongdan5485. Three levels of soil water content were used in two stages of water control levels at two stages of the maize plant development
1. The JOINTING STAGE: A. CONTROL (CK) soil water content: from 70% to 80% of soil water holding capacity at the field, soil water content: from 55% to 65% of soil water holding capacity at the field, soil water content: from 40% to 50% of the Soil water holding capacity at the field.
2. The BIG FLARE PERIOD: A. CONTROL (CK) soil water content: from 75% to 85% of soil water holding capacity at the field, soil water content: from 58% to 68% of soil water holding capacity at the field, soil water content: from 45% to 55% of the soil water holding capacity at the field.
This research mainly studied the effects of water deficit on physiological, morphology and the agronomical characteristics of the maize plant at the different water stress levels.
The importance of these results in this experiment will enable plant producers to focus and have a fair idea as to which stage of the maize plant’s development that much attention must be given to in terms of water supply. -
Study of animal welfare status in dairy cow herds in Hungary – looking for causes of lameness
25-29Views:116In the last 20-30 years, lameness in cattle was found to be third the most influential disease next to mastitis and reproduction disorders. Studies have been established to explore reasons for lameness and prevention. The problem with more robust prevention plans is that knowledge and research evidence is not strong enough to run an effective prevention plan. The aim of the research is to look for reasons of lameness by observing number of cows on 6 farms during 2 lactations. Performance data will be put together to body condition score (BCS) and lameness scores. Other examination is focused on monitoring of 40 farms. This part of the project is more related to extension, collecting and sharing solutions for decreasing lameness. Producers are advised what kind of measures are possible to reduce occurrence of lameness. Effectiveness of those actions will be measured at the end of the study. The first preliminary results show lack in almost all preventive measures needed to be taken in minimizing lameness. Those areas are related to poor facilities, lack of straw, problems with labor and basic management.
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In vitro analysis of the effect of ragweed extract against Monilinia laxa
117-120Views:103Nowadays in Hungary nearly 5 million hectares of agricultural area was infected with ragweed (Ambrosia artemisiifolia). According to the public opinion the ragweed is a weed. From agricultural and public health point of view it is exceptionally dangerous plant. As it contains a number of useful active ingredients, based on this the ragweed is consider a medicinal plant. Our goal was to present that the ragweed contains antifungal active substances as well. In the experiments we used the pre-flowering plants with roots and we extracted the biological active components of dried plant. We tested the biological activity of the extracts against Monilinia laxa in vitro. We related based on our examination that ragweed contains biologically active agents, by which it is hampered the reproduction of the Monilinia laxa.
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Andrological examination of Hungarian Large White and Landrace boars
5-10Views:209The Hungarian Large White and Hungarian Landrace pig breeds have outstanding lifetime performance, production parameters and crossbreeding ability. Nevertheless, during the recent decades, these breeds could not compete with the West European hybrid pigs concerning on production results. In this study, we made a complex andrological evaluation of boars in different Hungarian nucleus breeding stocks. After taking blood and semen samples, performing gonadotropin-releasing hormone (GnRH) challenge, ultrasonic and thermographic examinations were done. Laboratory tests were accomplished in reproduction labs of NARIC ABNMS. Our goal was to determine the reproductive performances of boars and collect samples for future genetic examinations, respectively.