The treatment of ketosis with glycerol was first introduced in the 1950s. Currently, the availability of glycerol as a feed supplement for dairy cattle has increased due to the rapid expansion of the biodiesel industry. It has been suggested that glycerol can be used as a dietary glucose precursor for dairy cows in a similar way to propylene glycol. This study examined the effect of orally administrated crude glycerol on milk production and composition, and energy-status related blood metabolites of primiparous (n=4) and multiparous (n=4) Holstein dairy cows in the first three weeks of lactation. The treatment group cows were given an oral drench of 500 mL of crude glycerol once a day before the morning feeding. Long-term oral drenching of crude glycerol had no effect on dry matter intake (DMI), but there was a positive effect on milk yield. Most milk composition values were not affected by the treatment, but treatment groups had lower milk protein levels. Blood glucose and insulin concentrations were declined with glycerol administration.

This study investigates different environmental effects on birth weight, weaning weight, and pre-weaning daily gain using different statistical models in the Latvian sheep population. The coefficients of determination (R2) were used to estimate the extent of different non-genetic factors influencing birth weight, weaning weight, and pre-weaning daily gain. Data were collected of 4460 lambs born in 36 herds during 2008 to 2010. The birth weight (on average 4.1 ± 0.01 kg), weaning weight (on average 21.0 ± 0.07 kg) and pre-weaning daily gain (on average 242.1 ± 0.93 g) was significantly affected by type of birth and sex, lambing age of dam (covariate) and herd, year, season of birth (p is less than 0.01). Coefficients of determination were estimated from 0.14 to 0.42 for birth weight, from 0.13 to 0.49 for weaning weight, and from 0.10 to 0.46 for pre-weaning daily gain. The results show that when the fixed effects of HYS (interaction between the herd, year, and season of birth) were included it improved the quality of the statistical model most of all, because higher determination coefficients were obtained for all traits: 0.42 for birth weight, 0.49 for weaning weight, and 0.46 for pre-weaning daily gain.

β-Carotene (BC) and a-tocopherol in milk fat have positive implications in human nutrition, besides the specifically protecting polyunsaturated fatty acids from oxidation. To determine the possible effect on some milk components, nutritional value and lipid stability of including carrots in the diet of lactating cows, ten cows were selected in a dairy farm and divided into 2 groups (control and experimental) by 5 cows in each. In experimental group's diet additionally 7 kg carrots per cow per day were included. Individual cow milk samples were obtained 1 day before feed enrichment, in days 7, 24, 35, 42 (during the feed enrichment), and 1 week after feed enrichment. Analyses of milk fat, protein content, somatic cell count (SCC), retinol, BC, vitamin C, tocopherols, immunoglobulins (Ig), lysozyme, fatty acids (FA) were made, and milk yield was measured. Supplying cow diet with carrots showed a tendency to improve milk quality by promoting the faster decrease of SCC, and significantly (p is less than 0.05) increasing Ig and lysozyme content, thus potentially improving milk nutritional value. The vitamin content rose significantly (p is less than 0.05) by retinol and tocopherol contents, but b-carotene content increase in milk was not observed. Also milk fatty acid (FA) stability changes during 5 day storage in temperature of 4 - 6 deg C were not observed.

Cereal grains have long been thought to be less important sources of antioxidants than fruits and vegetables although they contain many antioxidants and are major dietary components worldwide. The aim of the current research was to study and compare an antioxidant activity (AOA) and total phenolic content (TPC) of different barley varieties and malt types as well as to evaluate possible interconnection between TPC and AOA of barley and malt samples. The research was carried out on four lines of hull-less barley ‘3528’; ’L-400’; ’3475’; ‘3537’ and one variety of flaky barley ‘Klass’ grains, which were cultivated in Latvia in 2010, and their corresponding malt. Commercial sorts of malt - Pilsener, Munich, Caramel and Dark were used in the research to compare with the malt produced in the laboratory scale. The antioxidant potential of barley and their products is analyzed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Total phenolic content of barley and malt samples was determined according to the Folin-Ciocalteu spectrophotometric methods. The values of DPPH radical scavenging activity for 5 barley samples ranged from 4.57 to 5.89 μmol TE gE-1 DW. The total amount of phenols ranged from 1.96 to 2.43 mg GAE gE-1 DW for unprocessed barley samples and from 2.5 to 3.4 mg GAE gE-1 DW for their corresponding malt. TPC of malt commercial sort ranged from 3.5 to 6.7 GAE gE-1 DW. The increase of TPC for commercial malts is strongly related with Maillard reaction products.

Taste, smell and the flavour are the most important attributes determining the quality of bread or baked cereal products in general. Bread flavour is composed of hundreds of volatile and non-volatile compounds, i.e. many alcohols, ketones, aldehydes, acids, esters and other compounds. Many researchers have been studying volatile compounds in different breads worldwide, but in Latvia only few studies are conducted on volatile compounds in bread and its production stages. The aim of this research was to analyse the composition of volatile compounds during wheat dough fermentation. Experiments were done in 2011 and carried out in the Laboratory of Bread Technology and Laboratory of Packing Material Investigations at the Department of Food Technology in the Latvia University of Agriculture. An investigation of volatile compounds was done using solid-phase microextraction (SPME) and gas-chromatography mass-spectrometry (GC-MS). Volatile compounds were analyzed on the 10th, 20th and 30th minutes of wheat dough fermentation. In a fermentation process of wheat dough totally 15 volatile compounds were detected. Eight of them were alcohols, two aldehydes, two ketones, one ester, one acid and one terpene. Three volatile compounds – 1-octanol, caryophyllene and acetophenone, were detected in the dough samples only after 30 minutes of fermentation – those were not detected at the earlier stages of fermentation. The peak areas of 11 volatile compounds increased, but peak area of one volatile compound decreased along the fermentation time. The study proved that solid-phase microextraction can be used for detection of volatile compounds in wheat dough fermentation process.

Marinating is a simple technological treatment used to improve the tenderness and flavour of meat by soaking it in an aqueous solution which is composed of different ingredients. That also increases water brinding capacity of meat, thus reducing cooking losses and improving meat juiciness. The aim of current research was to investigate a degree of preference of marinated roasted venison meat. The red deer (Cervus elaphus) meat samples were obtained from a local farm “Saulstari 1”. The experiments were carried out in the Latvia University of Agriculture, Faculty of Food Technology. Prepared samples were marinated at 4 ± 2 deg C temperature in the refrigerator for 48 ± 1 h. After marinating, venison meat samples were wrapped in aluminium foil, and cooked on a pre-heated double hotplate grill at 200 ± 2 deg C temperature until ready to eat (45 ± 2 min). The cooked hot meat samples were sensory evaluated. The sensory evaluation was carried out by using the nine point hedonic scale – ISO 4121:2003. The sensory evaluation of meat sample with thyme and juniper berries showed that the degree of preference was not so high (approximately – 6.0 points). For the venison meat preliminary treatment mayonnaise and tomato sauce marinades possibly could be recommended for acquiring better sensory properties of ready to eat product.

Highbush blueberries are thought to provide protection against oxidative damage of free radicals and contribute to positive health benefits. They have been studied little in Latvia; therefore, the aim of study was to evaluate the soluble solids content, titratable acidity and sugar content of berries harvested in 2010. Seven varieties of cultivated highbush blueberries (Vaccinium corymbosum L.) grown in Latvia were analysed. Analyses were done for frozen berries of varieties ‘Bluecrop’, ‘Chandler’, ‘Chippewa’, ‘Duke’, ‘Northblue’, ‘Patriot’ and ‘Polaris’. All experiments were performed at the Latvia University of Agriculture, Faculty of Food Technology. The content of titratable acids (TA) was detected using standard method ISO 750:1998 by titration with 0.1N NaOH. Soluble solids content (SSC) was analysed using standard method ISO 2173:2003 by hand refractometer. Sugars (fructose, glucose and sucrose) were analysed by high-pressure liquid chromatography HPLC analysis. Results showed that there are significant differences between varieties (p is less than 0.05) for all parameters. TA content varied from 0.4 – 1.2%, SSC - 8.5 – 10.8 degBrix and total sugars from 7.6 to 9.3 g 100 gE-1. The highest ratio between sugars and titratable acids was for ‘Polaris’ while the lowest – ‘Chandler’ and ‘Bluecrop’.

Quality assessment of a study programme is a topical issue in the single education area. Quality is not a unequivocal term in higher education area, which lends itself to many understandings and interpretations according to different criteria. The best practice of software engineering may be applied for the study programme evaluation if by analogy it is viewed as software product. Study programme similar to software product has internal and external quality. Students as direct users of the study programme may be engaged in the evaluation of its external quality, in case the evaluation of internal quality of the study programme is mainly based on internal resources of a higher education institution. The paper provides the methodology for evaluation of external quality of a study programme based on software product quality model and quality assurance standards. Approbation of the methodology was started in 2009 at the Faculty of Information Technologies, where students evaluated external quality of undergraduate study programmes. Results obtained during the approbation lead to the conclusion that the chosen methodology ensures significant information for the enhancement of quality of a study course and simultaneously the entire study programme.

Metabolic analysis is one of the research focuses of systems biology. Two aspects of metabolic networks -network topology and stoichiometry - are what current researchers are most interested in, and both studies have revealed significant information. The research of the stoichiometric matrix of metabolic network has generated a series of powerful methodologies such as flux balance analysis (FBA). For FBA different methods execution are used different software like COBRA Toolbox and FBA-SimVis. The aim of this paper is to compare and analyze functionality of these two toolboxes, metabolic network data conformation conditions, and to compare all available FBA methods comparison in calculation possibilities and visual interpretation way. FBA, when analyzing all fluxes using different options, gives results in its metabolic network flow chart, although Cobra Toolbox returns the results in the matrix in number formats. FBA-SimVis for Steady state metabolic network models analysis is provided for a small metabolic network, because making some FBA analysis there are a ten possibilities to change an unlimited count of variables, to choose or change or optimize reactions as variables. Cobra Toolbox for Steady state metabolic network models analysis is provided for greater metabolic networks with hundreds or thousands of reactions. It allows changing an unlimited count manipulating and optimizing reactions fluxes.

Forest resources are Latvian national treasure that plays an important role in both ecology and economics of Latvia. Although a number of studies give summaries of statistical data, they have also been used as the basis for this study. Therefore, statistical analysis of the data on acquisition, regeneration, import and export of forest resources in Latvia has been carried out in this study. The aim of the study is to identify the available statistical information on the forest resources in Latvia by ascertaining the amount of available information, types of statistical data used in identifying information on tree felling, annual afforestation, import and export, and to carry out analysis of the acquired data. The statistical information has been obtained from the websites of the State Forest Service and the Statistical Office of the European Communities (Eurostat). As a result of the study, we have obtained the dynamics of tree felling and forest regeneration by dominant tree species. The study also reveals the dynamics of import and export of timber resources of the main products. The study was carried out in 2011, in Latvian.