National Repository of Grey Literature 22 records found  beginprevious13 - 22  jump to record: Search took 0.02 seconds. 
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.
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.
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.
Comparison of growth and survival of selected tench breeds in performance test
PRCHAL, Martin
This thesis is focused on comparison of performance traits of growth and survival of selected breeds of the common tench using the pure-blooded animal breeding method. The best way how to compare performance traits of particular breeds is through so-called performance tests. For this thesis following breeds were chosen: Vodňanské -(V), Hlubocké(H), Königswartha (German - N), Mariansko-Lázeňské (ML) and Romanian(R). The Golden tench were chosen as a control breed in order to correct the influence of the environment on the weight achieved. The testing began with selection and stripping preparation of spawners of relevant breeds selected for testing. Own performance test of selected groups proceeded from yolk - sac fry to the age of L2 in ponds with semi-intensive farming. Each tested breed was bred in the first growing period and in winter period together with the control group only. After group marking (the second growing period) by the cryogenic method, all breeds were bred together with triplication. In the first testing period reproductive parameters of spawners and their weight and survival of tested breeds were evaluated, in other period only weight and survival were evaluated. Reproductive parameters in males did not vary statistically in none of the parameters using any statistical method. In females significant differences were proved only between the breeds ?Hluboká? and the control breed. After the second growing period the highest weight was achieved by the Mariánsko-Lázeňské breed (112.9 ? 44.9 g), whose weight was statistically comparable only with German breed (105.4 ? 32.4 g). The survival after this period ranged from 70,4 % (Romanian breed) to 84,1% (Mariánsko-Lázeňské breed) and all breeds had statistically comparable values. The best performance traits after the second year of testing was achieved by the Mariánsko-Lázeňské breed.

National Repository of Grey Literature : 22 records found   beginprevious13 - 22  jump to record:
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