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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.
Afficher plus [+] Moins [-]Microbiological content of cow milk depending on season and herd size in Latvian organic farms
2014
Gulbe, G., Latvia Univ. of Agriculture, Jelgava (Latvia) | Valdovska, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The objective of the study was to investigate the microbiological content of cow (Bos primigenius) milk in Latvian organic farms according to season and herd size with a purpose to detect their impact on the distribution of mastitis causing pathogens in milk. Samples were collected in 14 organic dairy farms of Latvia, 4 times through 2012: in winter, autumn, spring and summer period. Raw milk samples (n=564) obtained from cow composite milk were studied. The samples were divided into three groups in accordance with the number of cows in the cow-shed: A (3-30), B (31-60) and C (61-124). The total colony count (TTC) and the isolation of mastitis causing bacteria were analysed using standard methods. Bacterial growth occurred in 90.4% of samples. Isolated microorganisms belonged to 35 species, and the following bacteria were the most prevalent agent, including Coagulase negative staphylococci in 29.4%, Staphylococcus aureus in 24.1%, Kocuria kristinae in 12.9%, and Enterobacteriaceae spp. in 10.3% out of 564 milk samples. Depending on the season, the average number of TCC was the lowest in summer (4.66 ± 4.01 log10 CFU mLE-1), moderately higher in spring and winter (4.72 ± 4.18 and 4.82 ± 3.54 log10 CFU mLE-1, respectively), but significantly higher in autumn (5.43 ± 4.80 log10 CFU mL-E1). Coliforms were not isolated from group A herds instead of B (3.1%) and C (4.6%). Occurrence of Staphylococcus aureus was noticeably higher in B (19.1%) and C (20.8%) than in A (12.6%) herds. Most of group A herds met the milk quality requirements, while group C herds produced more contaminated milk.
Afficher plus [+] Moins [-]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.
Afficher plus [+] Moins [-]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.
Afficher plus [+] Moins [-]Theoretical evaluation of hydrotreated vegetable oil application in diesel engines
2014
Sondors, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dukulis, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
A lot of different EU directives and regulations set the targets to decrease greenhouse gas emissions, to increase the share of renewable energy, and to improve energy efficiency. Biofuel usage is directly linked to all of these problems. Since the first generation food-based biofuels should not receive public support after 2020, investigations of next generation biofuels are topical. Hydrotreated vegetable oil (HVO) is one of the most promising next generation biofuels in the near future. This article deals with the results of mathematical modelling to determine the main diesel engine operating parameters (power, torque and fuel consumption) running them on HVO and its blends with fossil diesel fuel. The modelling results of the car Opel Insignia 2.0 CDTi show that every 5% of HVO in fuel blend reduces maximum power and torque of around 0.38% while raising specific fuel consumption by volume of around 0.10%. Analyzing the most realistic scenario in the near future – 7% HVO and 93% fossil diesel blend, the predicted fuel consumption increase (0.14%) and power and torque decrease (0.54%) is inconsiderable for vehicle exploitation, and HVO seems to be a promising biofuel to replace biodiesel in fuel blends and to promote reaching the EU targets.
Afficher plus [+] Moins [-]Spatial analysis of afforestation in Poland under rural development programme 2007-2013
2014
Kurowska, K., University of Warmia and Mazury in Olsztyn (Poland) | Kryszk, H., University of Warmia and Mazury in Olsztyn (Poland) | Marks-Bielska, R., University of Warmia and Mazury in Olsztyn (Poland) | Kietlinska, E., University of Warmia and Mazury in Olsztyn (Poland)
The paper covers spatial analysis of the Measure “Afforestation of agricultural and other than agricultural lands” implemented in Poland within the framework of the Rural Development Programme 2007 – 2013 (RDP 2007 – 2013). Beneficiaries obtained payments for afforestation based on the commitments made during the programming perspective of 2004 – 2006 or they joined the programme during the perspective of 2007 – 2013. Data obtained from the Department for Direct Payments of the Ministry of Agriculture and Rural Development as of 31 December 2012 formed the base of the analysis. Payments made in the country to the beneficiaries considering their activity and absorption of funds within the framework of the measure are presented. Next, given the disbursements made in voivodships and counties of Poland, the activity of beneficiaries was indicated and average disbursements per beneficiary were determined. The analysis aims at investigating the consistency of the afforestation policy implemented in Poland as of 2004 and showing the role of afforestation projects implemented within the RDP framework. The aim of the article is to show spatial changes in the intensity and dynamics of agricultural land afforestation projects implemented within the framework of the RDP 2007 – 2013 considering natural conditions. The afforestation rate and the ownership structure of the forestland in Poland is diverse. Afforestation allows and rationally manages agricultural land, which is of little use for agricultural production. The utilization of EU funds supporting afforestation of agricultural land in Poland is characterized by spatial variability.
Afficher plus [+] Moins [-]Biotic and anthropogenic risk factors in Norway spruce mixed stands management
2014
Ruba, J., Latvia Univ. of Agriculture, Jelgava (Latvia) | Miezite, O., Latvia Univ. of Agriculture, Jelgava (Latvia)
Latvia is one of the forest-richest countries in Europe. Very often in young forest stands of spruce admixture of coniferous or deciduous trees are taking place. During the growth trees suffer from influence of different risk factors. Damages in mixed stands depend on chosen mode and intensity of economic activities. Forest management cannot be imagined without creating the infrastructure (roads, ditches, etc.). However, the development of infrastructure may cause an effect of fragmentation and lead to changes in the forest structure. The aim of the research is to analyze influence of forest spatial features on the sanitary state of mixed stands of spruce. In 2011 and 2012 mixed stands of spruce younger than 40 years were investigated in all regions of Latvia. Nineteen stands were measured and surveyed and 80 sample plots were arranged. With the help of Geographical Information System (GIS) data base of the State Forest Service of Latvia the forms of forest plots (regular or irregular), as well as location of neighbouring infrastructural objects and location of mixed stands in forests were stated. In unnaturally created regular form plots damages of risk factors usually tend to be larger than in those, which have been created naturally. With the credibility of 95%, linear connection between occurrence of damages caused by browsing and intensity is relevant (r=0.937 is greater than r0.05=0.575), as well as occurrence and intensity of damages caused by Lophophacidium hyperboreum Lagerb. (r=0.999 is greater than r0.05=0.575).
Afficher plus [+] Moins [-]Climate suitability effect on tree growth and survival for Scots pine provenances in Latvia
2014
Rieksts-Riekstins, J., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Jansons, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Smilga, J., Forest Sector Competence Centre, SIA, Riga (Latvia) - MNKC | Baumanis, I., Forest Sector Competence Centre, SIA, Riga (Latvia) - MNKC | Ray, D., Forest Research, Roslin, Midlothian, Scotland (United Kingdom). Northern Research Station | Connolly, T., Forest Research, Roslin, Midlothian, Scotland (United Kingdom). Northern Research Station
Climate in Latvia has been changing in last decades, and it is predicted to continue changing; therefore, it is important for forestry sector to understand how these climatic changes might affect tree growth and survival. In order to assess climate suitability effect on Scots pine (Pinus sylvestris L.) provenances in Latvia, height and survival data from a Scots pine provenance trial located in three geographically distant places in Latvia were analysed together with several climatic indices. Provenances in the corresponding trial originated from Latvia, Poland, Germany, Belarus, Russia and Ukraine. Thirty year average climate data values from 1961 – 1990 for the 64 origins of provenances were acquired from the WorldClim project. Correlation analysis between provenance average values for height and survival and climate index values for the origins of the provenances confirm that there is a relation between these amounts, and the relation differs between the three site locations, indicating that suitability of climate is an important factor affecting the results of provenance trials. Cluster analysis confirmed that provenances from distant origins might have a very similar growth and survival rates; therefore, geographical location of the provenance origins cannot be considered as the only influential factor on these rates and the results from provenance trials have to be analysed together with climate data in order to make conclusions about the suitability of the provenances.
Afficher plus [+] Moins [-]Regional differences of final felling sawlog outcome in Latvia
2014
Grinvalds, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Pine, spruce and birch stem’s quality is different in regions of Latvia, but the differences are not included in the tables and models of assortment outcome. Therefore, it is not possible to predict accurately the outcome of round wood assortments. The aim of the research was to evaluate the regional differences of final felling sawlog outcome for Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.) and birch (Betula spp.) in Latvia and to set the regions with a different sawlog outcome. Data from 1645 final felling areas was used for pine, 1202 for spruce and 1531 for birch from the years 2010 – 2012. Firstly, the sawlog outcome of 97 territorial units was set by using the data of the final felling areas sawlog outcome of pine, spruce and birch. Secondly, territorial units with a similar sawlog outcome were consolidated in regions. The smallest regional difference of sawlog outcome was found for spruce (9.4%), slightly larger for pine (10.5%) and the largest difference for birch (16.2%). Three regions with the different sawlog outcome were found for Scot pine, six for Norway spruce and seven for birch. Several spruces and birch regions have similar sawlog outcome but those do not have borders. They are between regions with higher or lower sawlog outcome. Sawlog outcome of neighbouring regions differ for at least 4 – 5%.
Afficher plus [+] Moins [-]Problem rural areas in the region of Warmia and Mazury
2014
Gwiazdzinska-Goraj, M., University of Warmia and Mazury in Olsztyn (Poland) | Goraj, S., University of Warmia and Mazury in Olsztyn (Poland) | Nowak, M., University of Warmia and Mazury in Olsztyn (Poland)
Rural areas in Poland are vastly differentiated in their level of social and economic development. Adverse natural, social, economic and technological processes contribute to the formation of problem areas. Negative phenomena can spread across several municipalities, contributing to the number and severity of problems. Rural municipalities characterized by a low level of social and technical development are not attractive sites for prospective investors or home buyers. Geographical location can also contribute to the formation of problem areas. The Region of Warmia and Mazury borders the Kaliningrad Region, and it is one of the least developed areas in Poland. Rural areas in Warmia and Mazury are characterized by significant disparities in the level of social and economic development. The aim of this paper was to identify problem rural areas in the Region of Warmia and Mazury based on indicators of social, demographic, economic and infrastructure development. Problem areas in the Region of Warmia and Mazury were identified using Hellwig’s taxonomic measure of development. The results of our analysis indicate that in rural areas in the Region of Warmia and Mazury, the most severe problems are observed in typically agricultural municipalities which have a peripheral location and where state-owned farms had acted as the main employer.
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