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The impact of interspecific hybridization on fitness of Sturgeons
ŠACHLOVÁ, Hana
Sturgeons (order Acipenseriformes) are supposed to be one of the oldest groups of vertebrates still living on our planet. Moreover, their polyploid ancestry makes them very susceptible for interspecifc hybridization. These interspecific and intergeneric hybrids have been already described in nature as well as in captivity. Nevertheless, the fitness of sturgeon hybrids in comparison with pure species has not been studied yet even though it can have significant impact on sturgeon aquaculture production. The main goal of this study was to investigate and compare reproductive features (fertilization rate and hatching rate), survival rate and growth rate of artificially produced hybrids of Siberian sturgeon (Acipenser baerii) and Russian sturgeon (A. gueldenstaedtii) with their pure parental species. The experiment was performed till 262 day after hatching. It was supposed that these observed features could have significant impact on fitness of analyzed individual/groups. The highest reproductive features had hybrid between Siberian sturgeon (Acipenser baerii) females and Russian sturgeon (A. gueldenstaedtii) males while purebred group of Russian sturgeon displayed the lowest values of fertilization and hatching rate. At the beginning of the experiment, the highest survival rate was shown by purebred groups of Siberian sturgeon (Acipenser baerii) and Russian sturgeon (A. gueldenstaedtii), but this trend were slightly changed after 37th day post hatching. At the end of the experiment, the lowest value of survival rate was shown by purebred group of Russian sturgeon (A. gueldenstaedtii). Similarly, the lowest growth rate was also owned by purebred group of Russian sturgeon (A. gueldenstaedtii). In contrast, the best total growth rate was observed for hybrids between Russian sturgeon and Siberian sturgeon (A. geuldenstaedtii × A. baerii ) even though they grew slower until 101st day after hatching. Therefore, given the evidence discussed, this kind of hybrid could be suggested for intensive aquaculture and might be also suitable for polycultures stock. Finally, breeding of sturgeon hybrids might be seen as an effective alternative to pure species in sturgeon aquaculture, but suitable kind of hybrid must be selected.
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Different ways of using corn for forage purposes
SLANEC, Roman
Main focus of this thesis was to evaluate various ways of using corn as a provender and briefly mention economic and ecologic value of corn cultivation. According to the aquired data we can say that corn cultivation for provender has a growing tendency in the Czech Republic. Majority of corn is used in the form of silage. It is important to pay attention to agrotechnics, hybrid selection, cultivation and harvest in order to produce silage of high quality. Storage bags has shown better result both economically and in quality compared to silage reservoirs.
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Alternative drives of cars
Wachal, Ondřej ; Dvořák, Antonín (advisor) ; Hadrabová, Alena (referee)
My diploma thesis deals with alternative drive cars that are still more popular these times. Due to limited supplies of oil fields car factories turn their attention to the development of alternative drives, which would be independent of exhaustible resources. The aim of the work will mainly compare the economic efficiency of current alternative fuel vehicles, where belong hybrid drives, electric drives, but also a unit for compressed gas or biofuels, to the current conventional drives. This comparison will be done from the perspective of the end consumer who will decide on the purchase of alternative drive mainly because of its indicating cost savings. Another important part of the evaluation is whether alternative fuels are actually more environmentally friendly and are actually counted all the costs. For this analysis I will provide a variety of specialized studies dealing with the issue of alternative propulsion friendliness to the environment.
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Pig meat quality in selected final hybrids
VONDRUŠKA, Miroslav
The bachelor work was focussed on the area of the chemical composition, the physical and technological quality of meat, including the ageing processes in meat. Then there were described the quality indicators, that means pH, colour, luminosity of meat, viscozity of meat, texture of meat, percentage of intramuscular fat and the methods of their evaluation. Consequently were evaluated influences that affect the quality of meat that means the hybrid combination, sex, slaughter weight, nutrition and stabling. Pre-slaughter influences (transport to slaughterhouse, manipulation with pigs before slaughter, methods of stunning and killing) were included too.
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