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Faktory ovlivňující oplozenost násadových vajec v rodičovských chovech masného typu
Volná, Šárka
COBB, ROSS and HUBBARD are the most popular broiler chicks produced in the Czech Republic. The thesis looks into conditions required for achieving the highest number of hatching eggs produced from the ROSS 308 and the COBB 500 broiler breeders. The aim of the study is to find out factors which may production of hatching eggs and how a one hour shorter lighting program affects egg production. Broiler breeders between 20 and 51 weeks of age were studied in terms of the feed amounts in relation to the female body weight and effect on egg production, in the course of the whole laying period. Two farms had been investigated in the study. The one hour shorter light program did not affect egg production up to 35 weeks of age. Birds kept on 13 hour lighting program produced significantly heavier eggs compared to the birds with 14 hour lighting program. Till the age of 35 weeks females with lower initial body weights laid more substandard eggs in comparison with the ones with higher body weights.
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Productivity dynamics of herb layer in the thermophilous oakwood in the Nature Reservation Na Voskopě (Czech Karst) with respect to the solar radiation intensity
Mevald, Ondřej ; Černý, Tomáš (advisor) ; Josef, Josef (referee)
The Nature Reserve Na Voskopě is a special site where a long-term experiment was established in 2013, dealing with the switch of a long abandoned coppice back to its actively managed form. The project aims to examine the long-term impact of the proposed measures on the structure and diversity of plant species in herb layer especially in lighter woods at lower altitudes. The specific aim of this study was to examine the hypothesized crucial role of light conditions on the dynamics of plant biomass production in the undergrowth of such experimentally opened up thermophilous oak-dominated stand. A design was set up based on 40 permanent plots, where there were taken biomass samples from the herb layer in 2015. Further on, hemispherical images of forest canopy were photographed in the centre of each permanent plot. These images were evaluated in the analytical program WinScanopy, which calculates the amount of direct and diffuse radiation. The obtained datasets were evaluated by the regression analysis. The only decisive variable affecting the productivity of the herb layer turned to be diffuse radiation. The biomass data were also compared with light conditions sampled in the previous season (2014) as a part of ongoing experimental research. Season 2014 is characterized as a normal one and we managed to find a much stronger relationship between light conditions in 2014 and biomass productivity in 2015. Light conditions in season 2015 were significantly affected by the extremely dry and hot weather leading to strong defoliation of forest canopy. Still, we managed to demonstrate the positive impact of light conditions for the production of herb layer biomass. Weather extremes may also indicate an increase in biomass production in the next season, since a significant proportion of nutrients remained unused in the soil due to stopping the growth of vegetation. The current composition of the vegetation is very often determined by the extreme events in the abiotic environment occurring not long ago. Hemispherical images also proved as a very effective way to determine the light conditions, so it is also recommended to use for further research.
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Influence of Light Regime on the Success of Adaptation of Pike (\kur{Esox lucius}) Larvae on Pelleted Feed in RAS
DUŠEK, Tomáš
The objective of this thesis for a bachelor´s degree was to experimentally evaluate possibilities of adaptation of northern pike (Esox lucius) for controlled breeding conditions in the RAS and for intake of artificial pelleted feed. Special attention was focused on the influence of light regime on the success of adaptation and the rate of cannibalism. The experiment was divided into six groups with different light regimes (L8 : D16, L4 : D8 : L4 : D8, L12 : D12, L4 : D4 : L4 : D4 : L4 : D4, L16 : D8, L8 : D4 : L8 : D4). Into each group were putted 3,600 pieces of pike larvae, which means 20 pcs/l. Feeding was carried out manually in 15 minutes time interval. Daily mortality was recorded and biometric measurements were conducted. After 15 days, the experiment was evaluated. Adaptation for intake of pelleted feed was successful. As was found out, the light regime has the influence on survival, cannibalism and growth of northern pike in RAS. The highest final piece weight was achieved under the light regime L16 : D8 (W= 0,13135 ? 0,02924 g). The lowest final piece weight was achieved under the light regime L8 : D16 (W= 0,06296 ? 0,01306 g). The highest survival was achieved under the light regime L8 : D4 : L8 : D4 (61,36 %), the worst under the light regime L4 : D8 : L4 : D8 (28,33 %).
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