Grey alder occupies 190.6 thousand ha or 6.8% of forests in Latvia. Stand structure has influence on its productivity and dynamics. Materials for the studies were collected in the period from 2005 to 2007. For the investigation 47, grey alder stands, representing various ages, site index and density conditions from Jelgava, Bauska, Ogre, Aizkraukle, Jēkabpils, Valmiera, Talsi and Krāslava regions were used. The majority of these stands have not been managed previously and have been originated from shoots. A total of 11 – 30 - year - old grey alder stands were investigated using a 6 - tree sample plot method. Trees were grouped in 2 cm diameter classes according to breast height diameter. Trees according to reduction numbers were grouped in natural diameter classes. In 11 – 15 - year - old stands trees were within 4 - 5 two centimetre diameter classes, in 16 - 30 – year - old stands – within 6 - 12 classes. The proportions of trees in smallest and largest diameter classes not exceed 1 - 3%. The distribution of grey alder trees in natural diameter classes in 2/3 of cases match up with theoretical Tjurin distribution, resemblance was not detected in cases, when there are large proportions of thin trees in stand. Cumulative percent values of the number of trees and stand volume are were not dependent on site index. Relationship between cumulated value of the number of trees (y) in percents and cumulated value of stand volume (x) was described by parabolic equation (R2 = 0.997, p is less than 0.05). Fifty percent from stand volume were made up from 70% of thinnest trees. Regression equations describing dependence of tree height, height of live crown base, and length of crown from tree diameter were developed.

The vegetation of Pruno-Fraxinetum plant communities was described in 2004 – 2005 according to the Braun-Blanquet method throughout Latvia, in forests where common ash (Fraxinus excelsior L.) are dominant species in tree layer on moist soils. Classification of relevés (in total 52) by two way indicator species analysis (TWINSPAN) resulted in two variants of this association: typical variant (typicum) and variant with Filipendula ulmaria. Ellenberg indicator values were used to find out the relationship of flora with climatic (light, temperature, continentality) and edaphic (soil reaction, nitrogen, moisture) factors. Canonical correspondent analysis (CCA) was used to find out differences between two variants of Pruno-Fraxinetum. Results of this research have shown that these forests have complicated structure (form four vegetation layers, high species richness), which mainly depends on moist, rich eutrophic soils, usually with presence of limes. Main differential soil factors in ecological analysis are gradients of soil richness: moisture and nitrogen regimes. The influence of other factors was less expressed. Due to the human influence, especially drainage, the moist ash forests are decreasing and the species composition is changed. As Pruno-Fraxinetum forests in Latvia lie on the northern border of its distribution, the species composition differs from forests in the rest Europe; species characteristic determined by floodplain forests in Central Europe are absent.

Use of solar energy increases every year. In Latvia, solar energy is used mainly by solar collectors. The main part of the solar collector is the absorber, but not less important is the covering material which protects the absorber from the cooling impact of the wind. This cover must be transparent for solar radiation, but opaque for thermal radiation of the absorber, which is at greater wavelengths. Therefore it is important to measure absorption spectra of possible covering materials at visible and infrared wavelength ranges. Absorption spectra have been measured for several materials: glass, polythene, Plexiglas, and cells Plexiglas. Absorption spectra for all these materials are measured in three ranges: ultraviolet – visible (UV – VIS): 250 – 1000 nm; near infrared (NIR): 700 – 110 nm; infrared (IR): 1200 – 8000 nm. UV-VIS spectra with the ‘Ocean Optics’ device HR-4000 have been measured, but NIR and IR – with ‘Bruker’ Furje spectrometer EQUINOX 55. Evaluation of absorption spectra showed that the most suitable material (from the considered) for covering of solar collectors is Plexiglas.

Rising oil prices, national security concerns, the desire to increase farm incomes, and a host of new and improved technologies are propelling the European Union to set the directive for the year 2010 – each member state should achieve at least 5.75% biofuel usage of all used transport fuel. The report on the progress made in the use of renewable fuels shows that the average Member State of the EU has achieved only 52% of its target, and biofuels’ share in 2010 will not raise much above 4%. The prices of different biofuels are still not able to compete with oil based fuel prices. One of the possible ways how to solve this problem is to optimize biofuel supply chains using different methods of systems engineering. The aims of this investigation were finding out appropriate simulation tools for biofuel supply chain modelling, development of rapeseed oil supply chains for different production types, and modelling the developed supply chains. As the result of software survey, two packages were chosen – AnyLogic and ExtendSim Suite. Modelling studies showed that rapeseed oil supply chain is very sensitive, because changing just single parameters in a short scale, the actual cost price of 1 litre of oil changes considerably. Comparing the fossil diesel fuel prices with rape oil actual cost from modelling studies, the use of oil as a fuel for farm machinery seems to be profitable. Analysis of costs distribution shows that the greatest part is composed by rapeseed growing expenses.

This study was done to evaluate the prevalence and colonization density of helicobacters in the gastric mucosa of domestic dogs (Canis familiaris). Mucosal samples were taken from several places of cardiac, fundic and pyloric gland region of the stomach to detect helicobacters with urease test, brush cytology, and light histological examination. Fourteen dogs of fifteen sampled animals showed positive urease test and the presence of tightly spiraled helicobacters. Positive urease test was observed in 80.4% of all examined samples. Helicobacters were detected in 82.7% of all examined samples by brush cytology and 80.8% of all examined samples by histological examination. Compared to gastric regions, in all employed detection methods have been showed significantly higher prevalence of helicobacters in cardiac and fundic gland region than in the less effected pyloric gland region of the stomach. Histological examination showed the location and colonization density of the bacteria at the superficial epithelium, gastric pits, and deep glandular epithelium of the gastric mucosa in different regions of the stomach. Colonization density of bacteria was evaluated in 4 groups: as absent, mild, moderate, and severe colonization density of helicobacters. Occurrence of helicobacters in the cardiac and fundic gland region showed mild and moderate colonization density of helicobacters at the superficial epithelium and at the gastric pits of the gastric mucosa. Colonization density of spiral-shaped bacteria between the deep glandular epithelium was more pronounced in the pyloric gland region than in the cardiac and fundic gland regions of the gastric mucosa in the domestic dogs.

Researchers have found that morphology of muscle structure (original or after processing) is closely related to meat tenderness, which is very important attribute for consumer. The aim of the study was to evaluate changes in microstructure of poultry meat during the chilled storage. In the study, the cross-cut microstructure of parents stock hen and broiler muscles were analyzed during the storage at + 1 +- 0.5 °C temperature. The changes were determined for the following muscles: musculus pectoralis and pars praeacetabularis musculus iliotibialis lateralis in seven hours after slaughter and on the 7th day of storage. Parents’ stock (PS) hens were slaughtered on 61st week, but broilers at the age of 42 days (on the 6th week). The decrease in area of muscle fibres of hens and broilers' musculus pectoralis was found in both types of meat when comparing the sample on 7th hour and 7th day, but the smaller decrease was observed in broilers meat. Comparing muscle fibre area of broiler and hen pars praeacetabularis musculus iliotibialis lateralis [musculus biceps femoris] in hen meat it was reduced in higher proportion, but the distance between the fibres was increased reaching similar values for both sample types.

Iodine is a mineral that is added to the table salt and found in a variety of foods. It is important for good health and, fortunately, our bodies require it in minute quantities. Iodine is part of a hormone, thyroxin, which is responsible for maintaining a person’s metabolic rate. Iodine is the basic constituent part of the hormone of the thyreoid gland. On the whole, the amount of T3 and T4 correlates with the number of the iodine atoms. Therefore, without iodine the thyreoid gland cannot synthesize hormones and, therefore, cannot function. The role of iodine intake in both of these conditions was recognized in the 20th century, and since they are fully preventable through diet, public health advocates hope to entirely eliminate them at some point. Many things are natural sources of iodine. Saltwater fish and sea vegetables, for example, both contain abundant amounts of iodine. The material can also be found in plants grown on soil which is rich in sea materials, and in animals grazed on such soils. In some regions of Latvia, however, access to iodine is limited, and conditions like goiter, is realistic of iodine deficiency situations. In Latvia, some fear exists for manufacturers of food who use iodized salt. They are afraid that it will collide with changes of colour or taste of their products and will infringe on interests of the consumer. The main question for such problems is: is it a myth or the truth? In Latvia, starting using iodine salt in manufacturing, the most important question is: ‘What quantity of iodine remains after the technological processing?‘

Investigations of textural parameters of vacuum, protective gas atmosphere (MAP), and at air ambiance packed fresh carp (Cyprinus carpio L.) farmed in Latvia were carried out. The samples of carp were stored at two different temperatures (0 +- 0.5 and +4 +- 0.5 ºC) applying three different types of packaging – vacuum, MAP, and wrapping at air ambiance. Gas mixture used for MAP consisted of 40% CO2 and 60% N2. Samples were analyzed before packaging (day 0) and after 2, 4, 6, 8, 11 and 14 storage days. Textural parameters – hardness and shear force were evaluated by texture analyzer TA.XT.plus (Stable Micro System Ltd.). Two instrumental methods were applied for evaluation of textural properties. One method was based on compression test, using spherical probe, 25.4 mm in diameter (type P/1S), and measuring the hardness of the fillet and other method was based on cutting the fillet with a blade (type HDP/BSK) and measuring the shear force. The instrumental hardness and shear force of fresh carp fillets decreased during storage time. Texture variables significantly correlate with storage time, respectively, r = -0.723 and r = -0.748, the hardness and shear force. The storage time, temperature and packaging type with probability of 95 % substantially influence the textural parameters of carp fillets (P is less than 0.05).

Understanding the efficacy of organic trace minerals has been increasingly important over the past few years as a result of increased customer awareness of their benefits and the increase in the number of commercial products available to the customer. Organically bound trace minerals of interest in animal nutrition specifically include iron, zinc, manganese, copper, cobalt, and selenium. These elements have been shown to improve reproductive efficiency as measured by conception rate, alleviated calving, and reduced placenta expulsion rate. Additional benefits include improved growth performance of calves. The field trials in the period of 2005 – 2007 with Charolais breed beef cattle cows and calves verified efficacy of the premix PROTRACE G containing Fe, Zn, Cu, Mn, and Co chelates, Se-amino acid (selenomethionine), potassium iodide, and vitamins A, D3 and E. Average calving rate of experimental group cows fed diet with added premix was 20 – 30 min, placenta expulsion time - 28 – 31 min, but in control group fed only basal diet - 2 h 21 min and 1 h 30 min – 2 h 09 min (p is less than 0.05) respectively. Live weight gain of calves and heifers of the experimental group was on 35 – 39% higher (p is less than 0.05) than that in the control group.

The influence of non-genetic factors on lamb survivability at various ages up to 360 days was studied under village management condition in Jimma, Ethiopia. The overall least squares means of lamb survival rate was 89.0 at 0-60, 81.5 at 0-120 and 50.0 % up to 360 days. The survival rate of lambs up to weaning (120 days) was 81.5 %. Season of birth consistently exerted a significant effect (p<0.05)) on lamb survival. Lambs born during the post rain and dry periods showed a higher survival rate than lambs born during the wet season. Districts showed a significant effect (p<0.05)) on survival rates of lambs. Lambs born in land scarce areas (Dedo) had a low survival rate than lambs born in Seka (land available area). Type of birth did not exert an influence (p>0.05) on lamb survival. Sex had a significant effect (p<0.05) on survivability of lambs at later stages and the females showed higher survivability rate than males. Mortality tended to decrease with an increase with birth weight and decreased as parity increased. The birth weight showed a significant effect (p<0.05) on survival rate of lambs. The lambs with birth weight of 2 kg and above were showing higher survival rate. The lambs with 1.5 kg and lower birth weight showed high mortality rate. The study revealed that, adequate measures to be taken to curb mortality of lambs. The selection of heavier weight and larger litter at birth coupled with improved management could be a means to improve lamb productivity in the villages.