细化搜索
结果 311-320 的 2,098
Purification of egg yolk oil obtained by solvent extraction from liquid egg yolk
2014
Kovalcuks, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
There are different methods of egg yolk oil extraction, but still solvent extraction is commonly used. Due to the high cost of egg yolk powder production, extraction of lipids from liquid egg yolk remains very topical. Crude egg yolk oil obtained by solvent extraction from liquid egg yolk contains high amount of water which can decrease shelf life of egg oil promoting lipid oxidation. High concentration of residual solvents limits the usage of egg oil in food or in cosmetics due to the health risks. The aim of this study is to purify egg yolk oil obtained by solvent extraction from liquid egg yolk. Results show that it is possible to decrease the water content in egg oil from 14.26 ± 1.29% to 0.88 ± 0.13% by eliminating lecithin from egg oil. Solvent evaporation in the rotary film evaporator under the vacuum cannot remove solvents completely from the extract, but nitrogen streaming through the extract as a last step in evaporation process removes solvent residues, leaving behind high quality egg yolk oil suitable for food application.
显示更多 [+] 显示较少 [-]Jerusalem artichoke flour feeding effects on calf development in the first months of life
2014
Arne, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ilgaza, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Studies have been conducted to find out the effect of the feeding of calves (Bos Taurus) with Jerusalem artichoke (Helianthus tuberosus) concentrate produced in Latvia containing the prebiotic – inulin. The study was performed on two groups of animals - a control group of 8 animals and test (prebiotic) group of 8 animals in summer (from June to August, 2013), and winter (from December, 2013 to February, 2014) in one of cow farm of Latvia, in the municipality of Bauska. Both groups were fed the whole milk, but the test group received additionally 12 g of Jerusalem artichoke powder (an average of 500 g kgE-1 inulin) per day. The overall health status and physiological parameters (temperature, heartbeat and breathing frequency) of both animal groups before the study were of the normal range. After the experiment, we found out that the calves of the test group during both winter (one case) and summer seasons (seven cases), had fewer cases of diarrhea than the control (winter months four cases and summer months nine cases) group animals, the average daily weight gain (control group 0.53 g, prebiotic group 0.75 g) and the total weight gain (control group 29.42 kg, prebiotic group 42.13 kg) during 56 test days was significantly higher ( p is less than 0.05) than that for the control animals. We concluded that the use of Jerusalem artichoke flour concentrate when fed to the calves generally gives positive impact on the development and growth of the calves, improves the status of the gastrointestinal tract and the morphometric indicators.
显示更多 [+] 显示较少 [-]Alaria spp. epizootiological situation in wild boar in Latvia
2014
Berge, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Keidane, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
During the controls for Trichinella in wild boar meat, Alaria spp. mesocercariae in the examined samples are diagnosed. There does not exist a routine veterinary inspection for diagnosis of alariosis (Alaria spp.) in Latvia. The aim of the study was to determine Alaria spp. mesocercariae distribution in wild boar (Sus scrofa) meat in Latvia. Laboratory examination was performed in Latvia University of Agriculture Faculty of Veterinary Medicine laboratory of Parasitology, from 2010 to 2013. Meat samples were examined using artificial digestion method, which in regulation No 2075/2005 is considered an official detection method for Trichinella. In total, 1233 wild boar meat samples from different hunting regions of Latvia were examined. The territory of Latvia was divided into four regions – Kurzeme, Zemgale, Vidzeme and Latgale. For examination we used meat samples from wild boar pillars of diaphragm. Samples were taken from wild boars of different age and gender. The prevalence of infection in the examined wild boar meat samples from all regions was 8.2%, but the intensity of infection 2.8.
显示更多 [+] 显示较少 [-]Goat kids stomach morphological development depending on the milk type
2014
Otzule, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ilgaza, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
In goats (Capra) the growth and functional development of certain parts of the multi-chambered stomach continue during the first few months after birth. The aim of this research was to clarify morphofunctional changes in the kids abomasa and rumina and live weight gain during the first 8 weeks of life. Research was performed in two parts. In the first part (P1) we used Saanen breed kids which were all kept in the same conditions and in the second part (P2) we used Saanen breed kids which were separated in two groups with different feeding diets. In P1 the stomach contents of the goat kids were collected after slaughter (on day 1, 17, 25 and 30), weighed full and empty. The gastrohromoscopical method proved that in the newborn kids the area where the abomasal pH is 3.0 and lower is about 10% of the surface of the abomasum, but in age of three weeks it is composing 80% of the mucosal surface of the abomasum. In P2 were two groups – in the first group (MMG) kids which were fed with dairy (mother) milk and lived with mothers, the second group (MRG) kids were fed with milk replacer and lived separate from mothers. The stomach contents were collected after slaughter(at day 45 and 60).We confirm that the most important age of stomach development and kids growth in postnatal period are the first 45 days. During this period the most significant differences can be observed. On day 60 there are no significant differences (p is greater than 0.05) between MMG and MRG stomach development.
显示更多 [+] 显示较少 [-]Overview of Listeria monocytogenes caused abortions in cattle in Latvia in 2013
2014
Steingolde, Z., Latvia Univ. of Agriculture, Jelgava (Latvia);Institute of Food Safety, Animal Health and Environment „BIOR”, Riga (Latvia) | Avsejenko, J., Institute of Food Safety, Animal Health and Environment „BIOR”, Riga (Latvia) | Berzins, A., Latvia Univ. of Agriculture, Jelgava (Latvia);Institute of Food Safety, Animal Health and Environment „BIOR”, Riga (Latvia)
Listeria monocytogenes is a pathogen that causes infectious diseases in animals and foodborne infection in humans. The aim of this retrospective study was to analyse L. monocytogenes caused abortions in cattle in Latvia in 2013, and to describe the potential reasons of these abortions. In total, 186 cattle abortion cases were investigated. The pathological material from aborted foetuses included samples of brain, heart, liver, spleen, kidneys and lung, liquid of stomach and liquid from thoracic and abdominal cavities. These samples were tested with bacteriological methods according to ISO 11290-1:2007. L. monocytogenes was found in 44 (23.7%) cases of cattle abortions. Positive cases were more distributed in the central and the south-eastern parts of Latvia, because in this territory winters tend to be wetter and colder than in other parts of Latvia. Seasonality was observed of L. monocytogenes caused abortions and the majority of cases occurred during spring and autumn, when the cattle were fed with silage. All abortion cases were observed in the second and the third trimester of the gestation. L. monocytogenes caused abortions occurred in cattle of different ages, but significantly (p is less than 0.05) more often – in 3 years old cattle.
显示更多 [+] 显示较少 [-]Corticosteroid-induced alteration in liver function in dogs and its decrease possibilities
2014
Kondratjeva, J., Latvia Univ. of Agriculture, Jelgava (Latvia) | Birgele, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
Nowadays excessively used corticosteroids in veterinary medicine induce steroid hepatopathy in dogs (Canis lupus familiaris). The objective of this study was to determine the possibility of the hepatoprotectants to decrease the corticosteroid-induced alteration in such dogs’ blood serum enzymes as alaninaminotransferase (ALAT), gammaglutamyltranferase (GGT), alkaline phosphatase (AP) and corticosteroid-induced thermostable alkaline phosphatase (cAP). The study took place in private veterinary clinics in Riga, Latvia, during 2013, with the permission of dogs’ owners. Twenty eight animals, which received corticosteroids due to present diagnosis, were divided into two groups. In the first group long-lasting corticosteroid methylprednisolone acetate injection was used once, while in the second group the hepatoprotectants were used after the injection of corticosteroids. It was discovered that after 14 and after 30 days of hepatoprotectants use, blood enzymes were significantly lower (p is less than 0.05) than in dogs that did not receive hepatoprotectants. In both groups the enzyme values did not reach the reference limits. The study is set to investigate further if and when the values reach the reference limits.
显示更多 [+] 显示较少 [-]Clinical outcome of cutaneous mast cell tumors in dogs
2014
Kokorevica, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Matise-Van Houtana, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
A prospective study was performed on 15 client-owned dogs to assess the clinical outcome after surgical excision of canine cutaneous mast cell tumors (MCTs) depending on histologic grade and completeness of surgical margins. The surgical margins were evaluated as complete, close or incomplete if they were more than 3 mm, from 1 to 3 mm or less than 1 mm wide, respectively. Survival time for dogs with low grade MCT (based on grading by M. Kiupel et al.) was 409 days compared with only 60 days for dogs with high grade tumor. Dogs with high grade tumors had significantly shorter survival time and worse prognosis than dogs with low grade tumors (p=0.013). Complete excision was associated with lower possibility and longer time to tumor recurrence, as well as longer survival, however, marginal surgical border status did not have a significant impact on time to tumor recurrence and survival. It was also found that tumor duration but not tumor size had a significant impact on surgical margin status (p=0.047). Tumor size significantly affected survival time with larger tumors being correlated with shorter survival (p=0.03). The results of our study suggest that grade, tumor size and recurrence are significant factors for MCT prognostication.
显示更多 [+] 显示较少 [-]Heating of low-power induction motor under no-load mode and different cooling conditions
2014
Gedzurs, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The paper discusses heat transfer and the step response of a low-power induction motor to no-load mode under fan cooled and naturally cooled conditions. In Latvia University of Agriculture (LUA) in the electric drive laboratory the experimental tests were performed on a 1.1 kW totally enclosed fan cooled three phase induction motor with a fan mounted on a shaft for fan cooled conditions and with a fan taken off for naturally cooled conditions. The transient temperatures are measured in nine points of the stator end windings and in two points of the stator frame using thermocouples. Temperature is measured by using K type thermocouples and Pico-Log TC – 08 data logger. The current and voltage are measured by using Simple Logger II L562 two channel data logger. Measurement data are processed and archived using data loggers Pico-Log Recorder, Simple Logger II and Data View software. The experimental test results show that ventilation plays an essential role in the heating process of small power induction motors. Mathematical and virtual models of induction motor windings heating are represented to simulate the heating process of induction motor under no-load mode and different cooling conditions.
显示更多 [+] 显示较少 [-]Use of forest based biomass for bioenergy in EU-28
2014
Sikkema, R., European Commission, Ispra, Varese province, Lombardy reg. (Italy). Joint Research Centre. Inst. for Environment and Sustainability | Fiorese, G., European Commission, Ispra, Varese province, Lombardy reg. (Italy). Joint Research Centre. Inst. for Environment and Sustainability
Europe’s future wood demand for energy is expected to increase by 10 million to 200 million m3 in the period 2010- 2030. This will be supplied by both domestic sources (forests, industrial residues post-consumer wood waste), but also from sources outside Europe. The EU-28 predicts a near future (2020) gap between solid biomass supply and demand for renewable energy: 21.4 million tonnes of oil equivalents (MTOE). This is estimated via preliminary renewable energy action plans (NREAP’s) per country. The EU-28 expects wood pellet import will merely complete this gap of 21.4 MTOE, with more than 50 million tonnes of pellets. This implies a feedstock need of 125 million m3 of wood from forests and other sources outside the EU-28. A practical approach to include bioenergy in wood sector models should start with the input of wood pellets. Ideally, three types of bioenergy markets should be considered, in which pellets and the other major woody feedstock are included: 1. Large scale power production (the UK, Belgium, the Netherlands, all importing pellets from outside the EU-28); 2. Medium scale combined heat and power (CHP’s) including those in the forest sector (Nordic countries use pellets and chips for energy, merely imported from the EU-28); 3. Small scale residential heating (Germany, Austria and Italy, using wood pellets and logs from regional sources). We suggest starting with inclusion of medium scale CHP’s, followed by large scale power production. Small scale heating is relatively stable and should not have large impacts on future markets.
显示更多 [+] 显示较少 [-]The influence of forest distribution in the landscape of Lithuania on the amount of precipitation
2014
Tiskute-Memgaudiene, D., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Ruseckas, J., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
The influence of forest distribution in the landscape on precipitation in middle latitudes is poorly researched. Moreover, results of such studies are controversial. Nevertheless, most researchers agree with findings, that influence of landscape roughness formed by forests on the amount of precipitation is significant. This study aimed to extend knowledge of the interface between forest distribution and the amount of precipitation during particular periods. Database of the amount of precipitation from 31 Lithuanian meteorological stations during the period of 2002-2010 was used in this study. Findings defined statistically significant correlations in the amount of precipitation increase due to shorter Euclidean distance to the nearest forest edge in the particular landscape (r = -0.421 – -0.359), p is less than 0.05), also shorter distance of the meteorological stations to the nearest forests (r = -0.380, p is less than 0.05) and higher density of the forests, treated as a perimeter per area ratio (PAR) (r = 0.359 – 0.551, p is less than 0.05).
显示更多 [+] 显示较少 [-]