Spices are used to season food products. Investigations were carried out to determine dynamics of primary oxidation products in flavoured rapeseed oil depending on used spice, its concetration, storage duration, and sample preparing method. The oil was flavoured with winter savoury Satureja Montana L., hyssop Hyssopus officinalis L., and marjoram Oreganum vulgare L. Results showed that dynamics of peroxide value in flavoured oils were influenced significantly (p is less than 0.05) by all investigated factors - used spice, its concentration, storage duration, sample preparing method, and interaction of these factors, too. Heating of oil in particular cases caused unusual, hard explainable dynamics of peroxide value. It is necessary to investigate optimal conditions of flavouring of oils and components of spices which can influence oxidation of flavoured oils.

Natural defence mechanisms of the mammary gland tissues play a vital role in protecting the gland from infections. The progress of mammary infection depends on the ability of bacterial pathogens to adapt to milk and udder tissues, and on the various virulence factors they activate, as well as on the cow's response. The levels of immunoglobulins (lg) and lactoferrin (Lf) concentration in the milk from dairy cows with and without subclinical mastitis were determined. In this investigation it was stated that 82.5% of samples were negative, but 17.5% of samples were positive for pathogens. Cows had subclinical mastitis caused by Coagulase negative staphylococci observed in 48.60%, Streptococcus uberis - 32.10%, Staphylococcus aureus - 18.90% of cases in milk samples. There were no significant differences between all classes of immunoglobulins concentration in the milk without pathogens and with pathogens. The lactoferrin concentration was significantly increased for 40.33% in the milk with pathogens.

Due to large diversity of site conditions suitable for Scots pine growth in Latvia, it is important to evaluate their influence on growth and survival of particular Scots pine families. To do so, open pollinated progenies from phenotypically selected plus trees of 35 at the age of 32 years have been evaluated in 2 forest types (Cladinosa-callunosa and Hylocomyosa). Investigation revealed that forest type and family influence had a great significance to height, diameter at breast height, and diameter of thickest branch up to 2 meters' height (alpha is less than 0.001), but clone influence had lower significance (alpha=0.008). Proportion of influence to height growth caused by tree family was 70% at the age of 6 years and 17% at the age of 32 years. Proportion of influence on survival caused by tree family was 57% and 44% respectively. The corresponding influence of forest type was 12% and 28% to height, 15% and 39% to survival. Diameter at breast height at the age of 32 years was equally influenced by forest type and family (~11%). Equal breeding effect - but not with the same families - can be reached both in fertile and poor soils. In group (20%) selection this effect was ~8% for height, 11% for diameter, and 30% for survival; in individual selection ~10% for height, and ~17% for diameter.

Theoretical and experimental investigations are carried out to estimating the impact of the plough body working width on its specific draft resistance, as well as the ploughing efficiency. By using analytical correlations derived as a result of theoretical research, a computer algorithm has been worked out for simulating the functions of the plough body and the forces exerted by soil upon the operating parts, as well as its draft resistance. Specific draft resistance of the plough body, energy consumption, as well as labour efficiency and ploughing costs depend considerably on the working width of the body. By increasing it, the energy capacity, specific fuel consumption and expenditure decrease, but labour efficiency increases.

One of the prior trends of research is the problem studies of power economy of technological processes and quality automatic control. Though the theory of grain drying process has been developed profoundly, still there are problems in its implementation. The developed analytical and simulation models of grain drying are difficult to implement into practice because they do not contain all the factors, which influence the real grain drying process or they cannot be solved. The developed models enable to assess only the essentiality of factors and/or the fundamental basics of the process. In order to ensure the effective and user-friendly grain drying process, it is indispensable to develop the control methodology using system modelling approach. The present paper deals with the system approach to heat and mass transfer problem and the testing of the basic hypothesis of the diffusion theory about the normal distribution of particles in the diffusive environment.

Systainable energy systems and food security can be obtained in rural areas by usage of renewable energy resources and development of agro-ecotechnologies. Substitution of fossil feedstock for energy and raw materials by biomass is important measure also for greenhouse gas (GHG) emission mitigation. The article presents investigation of reed biomass size reduction processes flattening and cutting. The necessity to reduce the size of common reeds (Phragmites australis) to particles smaller than 3 mm for solid biofuel production is determined by compaction properties of biomass. It was stated that unflattened reed stem cutting energy consumption is 2 times more than flattened stem cutting energy. There are no sufficient differences in the energy consumption values for single flattened reed stalk cutting with different shaped knives. The average difference is approximately 2.4 kJ square m with knife edge angles 90 deg and 20 deg.

Same public goods can only be produced jointly with private goods. This paper focuses on the biological diversity that could be produced on semi-natural pastures through the assistance of grazing animals. The question that is being investigated is what shapes the total and marginal cost functions for biological diversity production on semi-natural pastures have if private goods are already being produced using livestock at farms near the pastures. The empirical analysis shows that a quadratic function describes the costs well and that the production is characterized by increasing marginal costs.

The results of synthesis and analysis regarding the structural diversity of farms, their differences, divergence and development in Jelgava district and Zemgale agricultural region are expanded in the article. Commercial farms and semi-subsistence farms are particularly studied on the basis of farm accountancy data.

Germinated grains are added to wheat dough with the purpose to promote the biological value of bread. As a result, a new product was obtained with a higher content of protein, fibre, B group vitamins; and vitamins C and E. The task was to investigate gluten quality changes at grain germination time, wheat dough rheological properties changes with various wheat, rye and barley amount additions, germinated for a different time. With the purpose to save maximum stability value of gluten, it was ascertained that the germination time of wheat grain could not be more than 24 hours. The best dough quality was obtained with germinated wheat grain additive. Germinated rye and barley grain additive (more than the experimentally ascertained amount) increases dough softening, decreases dough development time and dough stability. Only adding experimentally determined optimal amount of germinated grain, which promotes high quality bread, could produce dough with accepted rheological properties.

Accumulation of skatole levels in porcine fat tissue is a major reason for boar taint, an objectionable odour in meat from entire male pigs. In contrast to males, female pigs do not accumulate skatole in increased amounts. Hepatic metabolism is critical for the regulation of skatole. Cytochromes P4502E1 (CYP2E1) and P4502A6 (CYP2A6) are key enzymes involved in skatole metabolism. The objectives of this study were to evaluate the effects of gender and hCG stimulation on the activities of CYP2A6. Liver samples were taken at slaughter and analyzed for skatole concentrations, and for activities of CYP2E1 and CYP2A6. It was found that female pigs expressed higher CYP2E1 activity whereas activity of CYP2A6 did not differ between sexes. Skatole levels in the liver were higher in male pigs than in female pigs. Neither skatole levels nor enzyme activities were affected by hCG stimulation. It was concluded that the incidence of boar taint may depend on both the amount of skatole reaching the liver, and the activities of enzymes involved in skatole metabolism.