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Možnosti stanovení ethylkarbamátu v produktech kvasných výrob
Hlaváč, David
Ethyl carbamate, also known as urethane, is a carcinogen occuring in fermented foods such as bread, cheese, yoghurt and most in alcoholic beverages, especially in stone fruit brandies. 15 samples of fermented foods were analyzed in this work (2 samples of bread, cheese and yoghurt and 9 samples of alcoholic beverages) using gas chromatography. 5 samples were positive. Ethyl carbamte was detected in all of 3 samples of plum brandy in concentrations (9,94 +- 0,25) mg/l, (5,34 +- 0,41) mg/l and (4,03 +- 0,36) mg/l and in 2 vodka samples in concetrations (2,38 +- 0,25) mg/l and (0,26 +- 0,01) mg/l. Ethyl carbamate was not detected in bread, cheese and yoghurt samples as well as in Gin, Stará myslivecká, Apricot brandy and Gieroy vodka. However, the storage conditions of all samples were unknown.
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Vliv přikrmování upravenými krmnými komponenty v kapřích rybnících na kvalitu vody v recipientech
HLAVÁČ, David
Minimisation of environmental impact is a key factor in insuring the long-term sustainability of the aquacultural industry. Numerous studies have examined nutritional strategies as a means of reducing waste production and minimising the environmental impact of aquacultural waste. To achieve this goal, it is the challenge to the aquacultural industry to develop "environmentally friendly" feeds, feed management and feed production methods to reduce pollution. This applies mainly to pond farming of common carp, which plays an important role in global aquaculture. The objective of this Ph.D. thesis was to evaluate the possibilities of using modified cereals in pond aquaculture. It focused on issues that contribute to a better understanding of the interconnection between fish production, feed quality and applied feeding technologies with respect to water quality, nutrient budget, quality and quantity of natural food.
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INFLUENCE OF FEED PROCESSING TO PRODUCTION PARAMETERS IN MARKET CARP CULTURE AT TREBON FISCHERIES
HLAVÁČ, David
The aim of this study was to examine the production efficiency of processed triticale and compared to unmodified triticale during 135 day feeding experiment on ponds in the system Naděj. Dosing of feed, feeding technique and condition of the market carp in experimental ponds, the quality and quantity of natural food were observed. At the end of the experiment the main production indicators were evaluated and data were statistically evaluated. Higher production efficiency of mechanical and thermally processed cereals was not proved. The highest production efficiency was observed in variant with triticale supplementary feeding without processing (FCR ? 1.4; SGR ? 0.97 %.d-1; PER ? 6.74) and in variant with thermally processed triticale (FCR ? 1.63; SGR ? 0.88 %.d-1; PER ? 5.79). The lowest effective production was reached using grinded triticale (FCR ? 1.68; SGR ? 0.86 %.d-1; PER ? 5.62). Results were affected by different levels of quantity of zooplankton in the monitored ponds.
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