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Vliv zvolené strategie na efekt počátečního odchovu jesetera malého (Acipenser ruthenus) v kontrolovaných podmínkách
Dostál, Jan
The thesis summarizes findings from the field of initial rearing of sterlet (Acipenser ruthenus) that are currently available. The results of experimental rearing, which took place in 2014 and consisted of two parts, are included. In the first part, the impact of the exchange rate of the water in the tanks on change of hydrochemical parameters. For the experiment three variants in duplicate were prepared, with different flow rate for each one. The volume of water in the tanks was set to 100 liters and the number of fish was 150 fish/tank. Water change rate within the first variant was set for 1/3 of volume per hour, within the second variant for 1/3 of volume per hour and within the third variant for 3/3 of volume per hour. Each day was measured oxygen content, water temperature and pH, and samples for laboratory analysis were being taken. The results were analyzed by analysis of variance. No statistically significant difference has been found between monitored parameters, therefore these flow rates had no impact on the change of hydrochemical parameters for each variant. In the second part of the experiment was compared the effect of three different feed mixtures on growth parameters and development of fish. The same conditions of the rearing environment were maintained, but stocking density was reduced to 50 fish/gutter and a uniform water change rate of 3/3 volume per hour was set. The first variant was presented feed Aller Bronze 2 mm, the second variant Aller Silver 2 mm and the third variant Biomar Inicio 918 2 mm. At the beginning of the experiment, the fish reached an average piece weight of 29.00 g and FWC 0.44 within the first variant, 29.70 g and FWC 0.43 within the second variant and 29.31 g and FWC 0.41 within the third variant. At the end of the experiment the fish reached monitored parameters with following values: the first variant had the average piece weight of 37.99 g, FWC 0.41, SWGR 0.90 %.d-1, FCR 2.12 kg.kg-1 and PER 1,01; within the second variant, the average piece weight was 40.38 g, FWC 0.41, SWGR 1.02 %.d-1, FCR 1.82 kg.kg-1 and PER 1.18; within the third variant, the average piece weight was 43.51 g, FWC 0.40, SWGR 1.44 %.d-1, FCR 1.44 kg.kg-1 and PER 1.46.
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Ověření možnosti použití netradičních chovatelských postupů v chovu kapra obecného (Cyprinus carpio L.)
Kukačka, Vladimír
A series of four experiments has been made with the aim of monitoring the dynamic of change in the spectrum of fatty acids of common carp (Cyprinus carpio L.). In addition, the experiments also focused on the possibility of targeting changes in order to achieve a better dietary value of carp meat for human consumption. The changes in fatty acid spectrum of carp have been achieved by feeding of linseed and fish oil additions in a short interval, and by relaying fish with progressively decreasing temperature of water environment. From dietary point of view, the submission of feed containing 6 % linseed oil improved the FA spectrum of carp muscle when compared to the standard carp farming technology of cereal feed. The FA muscle fish spectrum, obtained due to the feed starting in early September 2008, endured without any considerable change through early January 2009. The application of fish oil is limited to qualitative composition. Through the addition of oils rich in EPA and DHA in the feed can effectively increase the content of the FA in muscle of carp.
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Effect of temperature, fish size and feeding on oxygen consumption and ammonia excretion in the Nile tilapia (Oreochromis niloticus)
DENKOVÁ, Adéla
Aim of this work were to assessed the impact of feeding, temperature, stocking density, fish size and water temperature on ammonia excretion and oxygen consumption of Nile tilapia (Oreochromis niloticus) in recirculating system. Concentration (saturation) of oxygen, water temperature and pH were measured using multimeter and concentration of ammonia was assessed by direct Nessler method. For assessing of effect of fish size, three groups of tilapias weighed 25, 65 and 140 g were established, each group in four replicates. For assessing of effect of feeding was tilapias (body weight 65g) divided into groups fed continuously, two meals per day and four meals per day, each group in four replicates. For assessing of effect of stocking density was tilapias (body weight 65g) divided into groups of 20, 50 and 80 kg.m-3, each group in four replicates. All experiments were performed for water temperature of 23, 27 and 31 °C and for fed and starved fish. Mean daily oxygen consumption was higher for smaller fish categories than for bigger ones and grow rapidly after feeding. The kind of feeding had impact on diurnal fluctuation of oxygen consumption. It was also confirmed that tilapia can survive low level of oxygen concentration for a quite long period.
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Podklady pro stanovení kompenzace za omezení hospodaření na rybnících a zemědělské půdě
Koutná, Jarmila ; Pražan, Jaroslav
Podklady pro stanovení kompenzace za omezení hospodaření na zemědělské půdě (zákaz používání všech hnojiv, zákaz používat biocidy, úplné vyloučení hospodaření, zákaz měnit současnou plochu a skladbu kultur, sečení, vyplocení, regulace pastvy a další omezení). Podklady pro stanovení kompenzace za omezení hospodaření na rybnících (snížení osádky buď jako primární změna managementu nebo jako následek omezení hnojení a/nebo přikrmování, úplné vyloučení hospodaření, omezení vyhrnování rybníků).
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Identifikace antropogenních tlaků v české části mezinárodního povodí řeky Odry
Výzkumný ústav vodohospodářský T.G. Masaryka, v.v.i., Praha ; Tušil, Petr ; Rešl, Jiří ; Luzar, Tomáš ; Pechar, Libor ; Máchová, Jana ; Sezimová, Hana ; Řehulka, Jiří ; Lojkásek, Bohumír ; Badurová, Jana ; Šajer, Jiří ; Krečmerová, Pavlína ; Šlouf, Vladimír ; Soldán, Přemysl
Identifikace antropogenních tlaků na stav půd, kvalitu vodních zdrojů a na změnu habitatu vodních ekosystémů s možností predikce či průkazu konkrétních dopadů na biologické komponenty dotčeného vodního ekosystému. Zpráva je rozdělena do pěti oblastí: 1. Bilance znečištění povrchových vod v povodí řeky Odry, 2. Průkaz a predikce antropogenních tlaků na biologické komponenty vodních ekosystémů, 3. Vliv intenzifikace chovu ryb na jakost vod, 4. Publikace výsledků řešení projektu, 5. Souhrnné hodnocení antropogenních tlaků v povodí řeky Odry. Nejproblematičtějšími parametry z množiny společných relevantních znečišťujících látek pro českou část MOPO (mezinárodní oblast povodí Odry) z pohledu národních limitních standardů jsou polyaromatické uhlovodíky a na úrovni evropských norem PAU a těžké kovy - rtuť a kadmium. Negativní vlivy se významně zesilují pod většími aglomeracemi. V povodí je neuspokojivá situace z hlediska možnosti rychlé detekce havarijního zhoršení biologické jakosti odpadních vod.
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