Plants are components of ecosystem that transfer elements from abiotic to biotic environments. Several elements, such as As, Cd, Hg, Pb, can be considered as food chain contaminants. Simultaneously, some essential micronutrients (e.g., Cu, Cr, Ni, Zn) at high concentrations may become toxic to both, plants and animals. To secure the aim to describe the uptake of metals by food crop species such vegetables, as radish Raphanus sativus L., leafy lettuce Lactuca sativa L. and dill Anethum graveolens L., were grown in soils of various grading composition and type. There were five soil types selected. A part of soils was contaminated with copper sulphate solution at different target concentrations, while another part was contaminated with mixture of metal (Pb, Cd, Cu, Zn) compounds. In half of treated soil samples the solution of humic substances was added. Harvested vegetables were dried, and after wet digestion with nitric acid quantitative analysis of metal concentrations was performed by use of atomic absorption spectrometry. The highest concentration of copper was detected in vegetable samples grown in soils with less organics, thereby indicating the importance of soil organic matter to metal transfer routes and accumulation rates in plants. Analysis of lettuce grown in soils contaminated with the mixture of metal compounds revealed that zinc was a metal absorbed more intensively, but metal uptake and accumulation was less intensive from peat if compared with other soils.

Ground beetles (Coleoptera: Carabidae) and rove beetles (Coleoptera: Staphylinidae) as predators of many pests and weeds in every crop are significant elements of integrated pest management. Worldwide studies show that ground beetles reflect different soil tillage methods, crop rotation, chemical and genetic pollution, usage of fertilizers and landscape fragmentation. All these factors are the parameters based on which it is possible to assess agriculture whether it is sustainable or not. Ground beetles also can indicate different farming systems and potentially serve as keystone indicators of pest abundance. Thus ground beetles can be good indicators of sustainable agriculture, but rove beetles have a good potential to do it. Researches on crop dwelling ground beetles and rove beetles have been done infrequently in Latvia. Mainly these are faunistic studies not paying attention to agricultural environmental factor effect to ground beetles and rove beetles. For using ground beetles and rove beetles as indicators of sustainable agriculture in Latvia, studies on these beetles reaction to different farming activities should be done. These studies must occur in different crops and different places of country, because ground beetle and rove beetle reflection to changes of agricultural environmental factors may be crop- and site - or even field-specific. Overview of literature on ground and rove beetles’ ecology in agroecosystems recorded in Latvia, other European countries and Northern America has been used for this study.

Horseradish (Armoracia rusticana L.) is a perennial herb belonging to the Brassicaceae family and contains biologically active substances. The aim of the current research was to determine the most suitable extraction method and solvent for obtaining horseradish leaf extracts with high antiradical activity. For experiments fresh leaves of horseradish were extracted with seven different solvents: n-hexane, diethyl ether, 2-propanol, acetone, ethanol (95%), ethanolwater/acetic acid (80/20/1 v/v/v) and ethanol / water (80/20 by volume) using two extraction methods (conventional and Soxhlet). For all extracts, total phenolic, flavonoid content and DPPH˙, ABTS radical scavenging activity, and reducing power were determined using a spectrophotometric method. As the best solvent can be used ethanol. Total phenolic content and total flavonoid content was higher in Soxhlet extracts. Comparing to other plants, the proportion of flavonoids in the amount of total phenolics is average, and it increases by increasing the polarity of used solvent. It can be concluded that by using Soxhlet extraction method it is possible to obtain extracts that are effective antioxidants. A very strong and a strong correlation has been identified between levels of phenolic compounds and antioxidant capacities of the extracts.

Nutritional value and shelf life of milk and dairy products depend on the composition and stability of their constituents. The aim of the present study was to evaluate the effects of carrots as cow feed carotenoid source on butter oil fatty acid (FA) composition and oxidative stability. Milk was obtained from one trial group (TG; n=5) and one control cow group (CG; n=5) in a conventional dairy farm in Latvia. TG cows received carrots 7 kg per cow per day; the length of the supplementation period was 39 days. The stability of butter oil exposed to sunlight (3h) and held for 14 days in the temperature of 60 °C was analyzed by peroxide value method. The changes of the FA content and ratios in TG milk fat were more positive with respect to the fat nutritional value as observed in CG – stronger increase in the content of polyunsaturated FA (p is less than 0.05), and in the ratio between stearic and palmitic acids (p is less than 0.05); also a tendency was seen of increasing content of short and monounsaturated FA, as well as decreasing the ratio between ω6 and ω3 FA groups. Oxidative stability of the carrot supplemented cow group’s milk butter oil samples that were collected after 25- day trial period, exposed to sunlight (3h) and stored at a temperature of 60 °C was significantly (p is less than 0.05) higher compared to CG samples. After the 39-day long trial period stability difference was not significant, despite the tendency that average polyunsaturated FA content in TG samples was higher compared to the control.

The main purpose of the research was to investigate the physically-chemical parameters of organic and conventional hull-less barley (Hordeum vulgare) harvested in Latvia. In the experiment the following hull-less barley harvested in 2012 from the State Priekuli Plant Breeding Institute (Latvia) was used: ‘Irbe’, PR4651, PR3808.21 and PR5099. The following quality parameters of grain – protein, starch, the bulk density and β-glucan content – were measured by standard methods – Infratec™ 1241 Grain Analyser (Denmark) corresponding to ISO 12099; thousand-grain weight (TGW) (ISO 520:2010); the falling number (ISO 3093:2009); moisture content (LVS 272:2000) were also determined. In the present experiments no significant differences in protein, moisture, starch, β-glucan content and TGW were detected, however, significant differences in the bulk density of all analyzed hull-less barley samples were established. The lower analyzed parameter value of 780 ± 1 g LE-1 was obtained for the conventional and organic hull-less barley PR 5099. However, the higher bulk density value of 821 ± 1 g LE-1 was obtained in the conventional hull-less barley variety ‘Irbe’. No significant differences in the bulk density of conventional and organic hull-less barley ‘Irbe’, PR4651 and PR3808.21 were found. Significant differences in the falling number were detected in the analyzed hull-less barley samples harvested in the conventional and organic farming. The lower falling number value was obtained in the organic hull-less barley line PR 5009 – 81 ± 4 s, the higher in the conventional and organic hull-less barley line PR 3808.21 as 362 ± 5 s and 373 ± 2 s, respectively.

Growing interest of consumers in healthy eating has provided the development of new range of food. Therefore the task of research was to determine the nutritional value, calculate energy value and investigate the sensory properties of yoghurt samples enriched with flakes from biologically activated hull-less barley grains and malt extract. Results showed that by adding flakes from biologically activated hull-less barley grain and malt extract it was possible to improve the nutritional value of yoghurt, i.e., increased protein, carbohydrate and decreased fat content. The energy value of yoghurt samples enriched with flakes from biologically activated hull-less barley grain and malt extract ranged between 65.96 and 75.72 kcal 100 gE-1, which is significantly lower comparing with mean energy value of commercial yoghurts. The changes of sensory properties were affected by the amount of added malt extract in yoghurt samples. The optimal amount of added malt extract for sensory evaluation in yoghurt samples was determined as 2%. The content of carbohydrate in yoghurt sample enriched with 5% of biologically activated hull-less barley grain and 2% of malt extract was two times lower than commercial yoghurts therefore its energy value was significantly lower. Yoghurt enriched with flakes from biologically activated hull-less barley grain and malt extract could be competitive.

The objective of the study was to examine how the circumstances of different bull daughters – Latvian Brown cow - group productivity levels correlate with the blood biochemical composition indices in Latvian conditions. The daughters of seven bulls, selected for our research trial, were kept in the same barn and under rearing conditions. Their blood samples were taken in a single sampling activity and analyzed for blood serum biochemical averages. Also Cu, Fe, Zn, Mn and Mg were detected in blood serum and the values found were compared with values fixed in regulatory documents. There were changes in Cu levels (daughter groups of four bulls), in Zn levels (one group); Mn level was lower in all groups and Mg level was higher in 6 groups. The altered biochemical parameters of blood were assessed from the pathogenetical point of view and compared with productivity averages in the progeny groups. The correlation factors suggested that there exist a strong positive correlation (p is less than 0.05) among a number of indicators, such as aspartate aminotransferase (ASAT) and protein r = 0.823; ASAT and somatic cell count (SCC), r = 0.737; blood protein and milk protein r = 0.903 - 0.917; albumins and protein r = 0.964; blood urea and milk protein r = 0.931 - 0.984 along with additional correlations. The correlation factors for the progeny group of each bull differed. The data obtained shows that the Latvian Brown cows crossed with other breeds produce cows with new genetic traits.

This article presents data on veterinary and sanitary evaluation of cows’ (Bovis) meat infected by leptospirosis. The material for the study was a sample of muscle tissue of m. longissimus dorsi taken at slaughter of 10 cows (Bovis) kept on farms in Almaty region. The following parameters have been examined in muscle tissue: water, protein, fat, ash, amino acid composition. Besides the biochemical studies we also measured pH of meat, put the reaction of neutral formalin (Formalin test) and determined the biological value of meat. It was determined that physical and chemical characteristics of sick animal meat have significant deviations from the norm. Such meat rapidly accumulates products of protein decay. The amount of essential and nonessential amino acids decreases, which indicates low nutritional value of meat. Meat of cattle infected by leptospirosis concedes by nutritional and biological value comparing to meat of healthy animals.

The research paper discusses simulation of the loading process of the vertical axis wind turbine with the permanent magnet synchronous generator. Experimental and analytical studies were done in the year 2013. The research results show that electrical load on the wind turbine generator is important for the wind turbine performance. If the load is above or below the power gained from the wind energy, the turbine operation cannot be considered efficient and its dynamic parameters fail to achieve the efficiency level at the proper operation load when the load is built up strictly in accordance with the wind energy input. In the research, 3 separate virtual electrical loading models with static, discrete, dynamic electrical load were established. MATLAB SIMULINK simulated virtual model shows the importance of usage of the right amount of electrical load in the vertical axis wind turbine with the permanent magnet synchronous generator. Final research results showed that the most effective loading process of wind turbine generator is a dynamic load.

The growing popularity of wooden panels renders this market segment increasingly competitive. The article describes a new type of fibre boards e.g. the furniture production, developed in cooperation with ATB (Leibniz-Institute for Agricultural Engineering Potsdam-Bornim) by using a new method of raw material preparation and specific production technologies of ATB. The main raw material is preserved hemp (Cannabis sativa) stalks. The samples are made of raw materials with different wet-preservation time and varying types of binder. For the first time there is used main raw material with short time wet-preservation. Samples that are 8 mm thick correspond to a medium-density fibreboard and that are 16mm thick correspond to a low-density fibreboard, fitting in its mechanical properties to standard BS EN622. On ATB’s experimental processing line 1,200x800x8 mm and 1,200x800x16 mm size board samples are produced and the tests are performed to determine such parameters as bending strength, thickness swelling and thermal conductivity according to EU standard methods.