A series of investigations were undertaken to provide information for compounders to consider when including fibrous foods in diets for growing pigs. The work involved measurements of nutrient digestibilities, growth trials and calorimetric studies. The digestibility of the neutral detergent fibre (NDF) fraction of a food was dependent on a number of factors including the source of fibre, the adaptation period and liveweight of the pig, and the protein and lipid contents of the diet. The level of addition of food fibre was not important in determining the digestibility of the NDF component of a fibre source, whereas an inverse relationship was found between the digestibility of nitrogen and energy, and the level of added food fibre. It was concluded that increasing the level of addition of food fibre is more important in determining the depressive effect on the digestibility of non-fibre components than its own. Rapid growth was achieved when young, weaned and growing pigs were given diets containing wheatfeed and sugar-beet pulp. A substantial part of the energy supplied was in the form of VFA produced by the fermentation of non-starch polysaccharides in the wheatfeed and sugar-beet pulp. A growth trial with diets containing sugar-beet pulp and maize revealed that fermented energy from beet pulp was used with an efficiency of 0.72 that of the energy of maize. The apparently digested energy arising from the fermentation of non-starch polysaccharides, therefore, does not correspond directly in terms of potential use to the animal with that obtained by the enzymic digestion of maize starch. A net energy value for sugar-beet pulp was also calculated. This work has shown that wheatfeed and sugar-beet pulp may be useful as dietary ingredients for growing pigs. However, growth rates may be slightly depressed due to a lower efficiency of utilisation of apparently digested energy from the fibrous fraction of the diet. This could lead to on farm problems associated with a decreased throughput eg overstocking. However, the use of a corrected digestible energy value and ileal digestibilities of amino acids for a fibrous food, when formulating rations, could lead to an improvement in the prediction in performance. As well as the nutritional aspects of feeding fibrous foods, there are also a number of non-nutritional factors which will influence the use of fibrous materials and these are discussed in the light of their practical implications for the feeding of fibrous foods to pigs.

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Oxidative stress contributes to inadequate in vitro maturation of porcine oocytes which leads to a failure of successful fertilization and embryo development. Therefore, the overall objective of this research was to characterize the mechanisms of oxidative stress in maturing oocytes and determine how oocytes alleviate oxidative stress with the assistance of supplemental antioxidants. A preliminary study was conducted to evaluate the effects of glutathione (GSH), N-acetyl-cysteine (NAC), and N-acetyl-cysteine-amide (NACA) supplemented to the maturation medium on intracellular GSH concentrations, nuclear maturation, fertilization success and embryo development. Antioxidants GSH, NAC and NACA (1.0 mM) were supplemented to the media during oocyte maturation. Intracellular GSH concentrations were recorded at 48 h of maturation and nuclear maturation and fertilization were analyzed 12 h after IVF. Embryo development was analyzed at 48 h and 144 h after IVF or intracytoplasmic sperm injection (ICSI). Supplementation of antioxidants had no effect on intracellular levels of GSH, nuclear maturation or fertilization traits. Blastocyst formation for NAC (35.0 ± 7.4%) and NACA (40.0 ± 7.4%) supplementation were higher (P < 0.05) than the control (20.0 ± 7.4%) and GSH supplemented (20 ± 7.4%) oocytes. The same pattern was seen for ICSI-derived embryos: blastocyst formation for NAC (22.0 ± 5.9%) and NACA (25.0 ± 4.6%) supplementation were higher (P < 0.05) than the un-supplemented (10.0 ± 6.0%) oocytes. There were no differences between NAC and NACA supplementation and there were no differences between the cleavage rates for any of the treatment groups. These results indicate that supplementing 1.0 mM of NAC or NACA to the oocyte maturation medium and the ICSI medium increased the percentage of viable embryos reaching the blastocyst stage of development, and could warrant further investigation. The next study was conducted to evaluate the effects of different concentrations of NAC supplemented to the maturation medium on embryo development. Comparisons of significant concentrations of NAC and NACA on embryo development were evaluated for nuclear maturation, fertilization success and embryo development. Concentrations of NAC (0, 0.5, 1.0, 1.5, 2.0, 2.5, 5.0 mM) were supplemented to maturing oocytes and embryo development was analyzed at 48 h and 144 h post-fertilization. There were no differences between cleavage rates for any of the treatment groups. Blastocyst formation for 1.5 mM NAC (56.5 ± 9.2%) was significantly higher (P < 0.05) than all other supplementations. There were no differences in nuclear maturation or fertilization when comparing 1.5 mM NAC and 1.5 mM NACA supplementation to the maturation media. There was no difference between cleavage rates of 1.5 NAC and 1.5 mM NACA supplementation to the maturation media. Blastocyst formation for 1.5 mM NAC (44.4 ± 4.7%) and 1.5 mM NACA (46.2 ± 3.4%) supplementation were significantly higher (P < 0.05) than the control (32.1 ± 6.2%) oocytes. These results indicate that supplementing 1.5 mM of NAC or NACA to the oocyte maturation medium increased the percentage of viable embryos reaching the blastocyst stage of development and could be used during the oxidative stress experiments. In the final study, the mechanisms of oxidative stress in maturing oocytes were studied in addition to evaluating the effects of antioxidant supplementation to the media. This study focused on superoxide dismutase (SOD), GSH peroxidase, catalase and intracellular GSH concentrations with respect to DNA fragmentation evaluated using the single cell Comet assay. Results indicate that when SOD was inhibited, the GSH peroxide levels and length of DNA migration significantly increased (P < 0.05). Catalase levels significantly decreased (P < 0.05) and intracellular GSH remained unchanged. When GSH peroxidase was inhibited, the SOD levels and catalase levels significantly decreased (P < 0.05) but the intracellular GSH and DNA migration length significantly increased (P < 0.05). The supplementation of 1.5 mM NAC and 1.5 mM NACA had multiple effects on the enzyme levels. Specifically, supplementation of 1.5 mM NAC or 1.5 mM NACA significantly decreased (P < 0.05) the length of DNA migration when other enzymes were inhibited compared to no antioxidant supplementation. These results indicate that antioxidant supplementation may alleviate the free radicals associated with oxidative stress in the maturing porcine oocyte. In conclusion, supplementing the antioxidants NAC or NACA to the oocyte maturation media does not have negative effects on IVF or embryo culture. Supplementation of NACA increases the number of oocytes reaching the blastocyst stage of development. Glutathione, SOD, catalase, and GSH peroxidase are all required to be functional during oocyte development to alleviate oxidative stress on the oocyte. Antioxidants enhance the enzyme activity during oocyte maturation and may even contribute to protecting the oocyte when enzyme activity is impaired. / Ph. D.

The petroleum industry faces problems in transportation of crude petroleum be- cause of the deposition of paraffins, hydrates and asphaltenes on the insides of the pipeline. These are conventionally removed using either chemical inhibitors or mechani- cal devices, called pigs, which travel through the pipeline and mechanically scrape away the deposits. These pigs are propelled by the pipeline product itself and hence travel at the same velocity as the product. Research has indicated that cleaning would be better if the pigs are traveling at a relatively constant velocity of around 70% of the product velocity. This research utilizes the concept of regulating the bypass flow velocity in order to maintain the pig velocity. The bypass flow is regulated by the control unit based on the feedback from the turbine flowmeter, which monitors the bypass flow. A motorized butterfly valve is used for actually controlling the bypass flow. In addition to cleaning, the proposed pig utilizes on-board electronics like accelerom- eter and pressure transducers to store the data gathered during the pig run. This data can then be analyzed and the condition of the pipeline predicted. Thus, this research addresses the problem of designing a pig to maintain a constant velocity in order to achieve better cleaning. It also helps gather elementary data that can be used to predict the internal conditions in the pipe.

The aim of this thesis was to evaluate the pig fattening at the school farm in Měšice. The work is concern with the evaluation of the fattening period, the production and realization price of the pigs. The monitoring was conducted from 2010 to 2011. The evaluation included a total of 1994 pigs. The thesis take into consideration not only the initial and final weight of the animals, the losses, duration of the fattening period and the average slaughter weight, but also the total costs of their fattening. The statistical analysis was performed using Microsoft Excel. To evaluate the results the monitored indicators were calculated as average values and differences between data. When taken into the pre?fattening in 2010 the average weight reached 5.10 kg per piglet. In 2011 this figure dropped to 5.05 kg. The average weight of pigs sold in 2010 was 107.35 kg. It declined in 2011 to 101.27 kg. In 2010 the school farm in Měšice achieved an average daily weight gain of 0.67 kg. This number increased in 2011 to 0.74 kg. The average fattening cost per pig/day, during the reporting period in 2010, was 26.07 CZK. There was an increase the following year by 0.89 CZK to the amount of 26.96 CZK. When selling the pork meat in 2010, the average realized price by the farm was 26.46 CZK/kg. In 2011, the average realized price rose by 2.35 CZK / kg, thus increased to CZK 28.81CZK/kg Considering all the indicators and the production costs of the pig meat, the farm encountered a loss for the entire reporting period.

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