The natural fibers as reinforcing elements of the polymeric matrices of composite systems

katedra: KMT; rozsah: 34 s.Předmětem diplomové práce je seznámení s přírodními rostlinnými vlákny a jejich využitím jako vyztužujících prvků vícesměrných kompozitních systémů s polymerní matricí. Za přírodní vlákna byl vybrán bambus a technické konopí. Polymer použitý jako matrice kompozitního systému byl polypropylen. Pro zlepšení kvality vytvářeného mezifázového rozhraní mezi vyztužujícími vlákny a matricí, vzniklého v důsledku spojování hydrofilního a hydrofobního materiálu, bylo použito studené plazma, kterým byl modifikován povrch práškového polymeru. Za účelem dosažení různé povrchové modifikace byly jako pracovní plyny použity kyslík a vzduch.The aim of diploma thesis is an introduction of the natural fibers and their using as reinforcing elements of the multi-axials composite systems with the polymeric matrix. Bamboo and industrial hemp have been selected as natural fibers. Polypropylene has been used as the matrix material of composite system. Cold plasma, by which has been modified surface of powder polymer, has been used for improvement of quality an interphase boundary between the reinforcing fibers and the matrix, that have been made as a result of coupling the hydrophile and the hydrophobic material. Oxygen and air have been used as working gases for purpose to enhance various surface treatment

Effect of feeding of different sources of NPN on production performance of dairy cows.

Received: 2016-04-11 | Accepted: 2016-05-04 | Available online: 2016-12-22http://dx.doi.org/10.15414/afz.2016.19.04.163-166The aim of the study was to analyse the effect of feeding of different sources of NPN on nutrient utilization and production performance of dairy cows under field conditions. Balancing diets for crude protein without consideration of protein quality or rumen degradability often led to overfeeding of nitrogen and less than optimum production. High yielding dairy cows separated in two groups with 85 resp. 80 cows in each were set up for the trial. Groups were consistent according the stage of production and reproduction cycle as well as age structure. Both groups were fed concentrate mixture with the same composition with only difference in NPN/ microbial protein source, with same dosage of 100 g per cow and day. Field trial was performed for period of 3 subsequent months. Performance data were collected in accordance with official milk recording. In both groups majority of cows were on first lactation. Significant differences in daily milk production were observed 2.87 kg (P<0.01) for group 2, in fat content 0.07 % for group 2 non-significant, whereas in protein content 0.18% for group 1 significant (P<0.01) in case of first lactations. If considering  first tree lactations, group 2 produced 1.7 kg milk per day more (P<0.08), with 0.05% fat more and 0.002 % protein less than group 1. The space created in dry matter intake by a concentrated slow-release NPN can be filled with high quality forage that could reduce the cost of feeding while maintaining levels of production. Keywords: Holstein, slow-release urea, microbial protein, milk yieldReferences Bíro, D., Gálik, B., Juráček, M. et al. (2009) Effect of Biological and Biochemical Silage Additives on Final Nutritive, Hygienic and Fermentation Characteristics of Ensiled High Moisture Crimped Corn. Acta Veterinaria Brno, vol. 78 (4), pp. 691-698 doi: http://dx.doi.org/10.2754/avb200978040691Bouška J. et al. (2006) Chov dojeného skotu, Profi Press, Praha, 2006Cantalapiedra-Hijar, G., Peyraud, J. L., Lemosquet, S. et al. (2014) Dietary carbohydrate composition modifies the milk N efficiency in late lactation cows fed low crude protein diets. Animal, vol. 8 (2), pp. 275-285 doi: http://dx.doi.org/10.1017/S1751731113002012Cappellozza, B. I., Bohnert, D. W., Schauer, C. S. et al.  (2013) Daily and alternate day supplementation of urea or soybean meal to ruminants consuming low-quality cool-season forage: II. Effects on ruminal fermentation Livestock Science, vol. 155 (2-3), pp. 214-222 doi: http://dx.doi.org/10.1016/j.livsci.2013.05.002De Boever, J. L., Blok, M. C., Millet, S. et al. (2014) The energy and protein value of wheat, maize and blend DDGS for cattle and evaluation of prediction methods. Animal, vol. 8(11), pp 1839–1850  doi: http://dx.doi.org/10.1017/S1751731114001815Harrison, G. A. and Karnezos T. P. (2005) Can we improve efficiency of nitrogen utilization in the lactating cow? Recent Advances in Animal Nutrition, vol. 15, 2005, 001-011pp.Hazuchová E. and Kasarda R. (2010) Evaluation of body condition score of lactating cows. 61st EAAP Annual Meeting, Heraklion. 2010. Book of Abstracts. 34, 26,p. 375Holder  Vaughn B., El-Kadi, Samer W., Tricarico, Juan M. et al. (2013) The effects of crude protein concentration and slow release urea on nitrogen metabolism in Holstein steers. Archives of Animal Nutrition, vol. 67 (2), pp. 93-100 doi: http://dx.doi.org/10.1080/1745039X.2013.773647Kudrna V. and Homolka P. (2009) Vliv diety, zejména obsahu dusíkatých látek, na množství a kvalitu mléčné bílkoviny a zdraví dojnic, Výskumný ústav živočišné výroby, Praha – Uhříněves, 2009McGuire D. L., Bohnert, D. W., Schauer, C. S. et al. (2013) Daily and alternate day supplementation of urea or soybean meal to ruminants consuming low-quality cool-season forage: I-Effects on efficiency of nitrogen use and nutrient digestion  Livestock Science, vol. 155, (2-3), pp. 205-213 doi: http://dx.doi.org/10.1016/j.livsci.2013.05.015Šimko, M., Čerešňáková, Z. Bíro, D. et al. (2010) Influence of Wheat and Maize Starch on fermentation in the Rumen, Duodenal Nutrient Flow and Nutrient Digestibility. ActaVeterinaria Brno, vol. 79 (4), pp. 533-541 doi: http://dx.doi.org/10.2754/avb201079040533Zeman, L. et al.(2006)  Výživa a krmení hospodářských zvířat., Profi Press, Praha, 2006

INFLUENCE OF SILAGE ADDITIVES ON FERMENTATION OF HIGH MOISTURE CRIMPED CORN

The objective of this work was to find influence of different silage additives on silages fermentation and nutritional value made from high moisture crimped corn, which were conserved in semi experimental conditions. Three variants were examined, untreated control (C), and two experimental variants conserved by biological (variant A) and chemical (variant B) additives. The maize crimped corn was hermetically filled into plastic bins with the capacity 50 dm3. In silage conserved by additives was lower content of crude fibre (significantly in both experimental variants) and higher content of nitrogen free extract, starch and total sugars (significantly in variant A) established. In silages form both experimental variants we found significantly lower content of lactic acid. The highest concent we detected in silage conserved without additives. In silage conserved by biological inoculant we found lower content of acetic acid and higher content of butyric acid, but their content was generally very low. Additives used in the experiment decreased content of amonia (0.074 g.kg-1 in variant A and 0.095 g.kg-1 of dry matter in variant B) and alcohols too

The effect of dha omega-3 feeding in the high yielding holstein herd

The aim of this study was to analyse the effect of supplementary feeding of DHA (Docosahexaenoic Acid) rich algae product (Algae STM Alltech Inc.) on production of milk, fat and protein as well as on reproduction of high yielding Holstein dairy herd. Field trial was set up on Top 10 dairy farm in western part of Slovakia, under commercial conditions. The data of high yielding dairy cows, separated in two groups of 30 (control) and 29 (trial) animals, were recorded for period of 3 subsequent months from October to December 2015. Animals were fed once a day Total Mixed Ration based diet with different feed mixture composition in trial group (+100 g Algae STM Alltech Inc. per cow and day). Performance data were collected in accordance with official milk recording system of Breeding Services of Slovak Republic s. e. and milk samples were collected once per month according to the A4 standard methodology. The control group showed higher level of milk production compared to trial. Our study indicated that the feeding of algae caused milk fat depression and generally lower protein content in milk. Significant impact of algae feeding was found also for the level of urea in milk. In addition, the supplementary feeding of DHA may represent effective strategy to increase the percentage of pregnancies per inseminations in lactating dairy cows

Application possibilities of thermovision technique in diagnostics of aerial systems of radio transmitters

The paper deals with possibilities of use of thermovision technique in diagnostics of aerial systems of radio transmitters. Graphically presented: heating characteristic of the junction at the transmitter power of 60 % (slack and polluted junction); relationship between temperature of connection (feeder ‐ line, capacitor frame) spacing collar and power; relationship between temperature rise amount of connection and feeder line upon power; thermogram of the junction feeder line ‐ spacing collar, capacity frame; thermogram of the junction feeder line ‐ spacing collar. First Published Online: 27 Oct 201

IMMUNOGLOBULINS IN COLOSTRUM OF SOWS WITH PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME - PRRS

The aim of this study was to examine the effect of PRRS occurrence on sow colostrum immunological quality. We realised the experiment on 20 sows (breed: Large white). From farm without presences of PRRS were 10 sows and other 10 sows were from farm with presence of PRRS. We took the samples of sows colostrums during sucking. We detected concentration of immunoglobulins (IgG, IgA, IgM) in sows colostrum in time of 0 hours to 12 hours after beginning of farrowing with pig Ig ELISA quantitation kits. We determined statistically significant (P0.01) higher concentration of IgG at the beginning of farrowing, 3 hours, 6 hours and 12 hours from beginning of farrowing in favour of farm without presence of PRRS. We determined statistically significant (P0.01) higher concentration of IgA at 6 and 12 hours from beginning of farrowing in favour of farm without presence of PRRS. We determined statistically significant (P0.01) higher concentration of IgM at 6 and 12 hours from beginning of farrowing in favour of farm without presence of PRRS. Lower concentrations of colostral immunoglobulins in group with PRRS can be caused of presence of PRRS. Virus PRRS can evocate synthesis of cytokine IL-10, which inhibited the function of macrophages and lymphocytes and so PRRS decrease the production of immunoglobulins and their concentration in blood of sows and consequently also concentration of immunoglobulins in sows colostrum