Heat is one of the most important types of energy at northern latitudes. In 2013 the total consumption of renewable energy resources (RER) in Latvia was 68 PJ. The heating systems can function on plant or other organic material, for example, wood chips or agricultural residues. By using local biomass resources it is possible to reduce the pollution of atmosphere caused by greenhouse gas emissions. Different variety of winter wheat (Triticum aestivum), triticale (Triticosecale) and rye (Secale cereale) were used in the research. The following aspects were determined during the research: dry matter yield, chemical composition and the higher heating value of grains and straw. The evaluation of grains and straw of winter cereals showed that the higher heating value (MJ kgE-1) was acquired from the straw of winter cereals, whereas the grains had the highest dry matter yield, thus the grains of winter cereals had the highest heating yield from one hectare (GJ haE-1).

The experiment was carried out at the Research Centre of Organic Farming of Estonian University of Life Sciences in 2012 and 2013. The study was aimed to find out the effect of defoliation and humic acid application on the strawberry (Fragaria × ananassa Duch.) plant growth, yield, and on the ascorbic acid, total phenolic and anthocyanin contents in ‘Darselect’ yield. Defoliation decreased significantly the number of leaves and inflorescences in both experimental years, while the fertilization effect was only in one experimental year. Fruit weight ranged from 19 to 42 g, being significantly decreased by defoliation in 2012, but increased in 2013. Yield was decreased due to defoliation up to 40% in 2012 and up to 51% in 2013, but humic acid application increased the yield of the defoliated plants in both experimental years. Defoliation in combination with humic acids had a significant effect on strawberry ascorbic acid content, but the effect was different for different fruit order. Tertiary fruits contained up to 46% more of total phenolics due to defoliation in both experimental years. Defoliation increased anthocyanins in primary and secondary fruits, but decreased it in tertiary fruits; while fertilizing increased the content up to 45% in defoliated plants in primary, but decreased about 13% in tertiary strawberries.

This research was conducted to determine the chemical composition of smooth bromegrass in artificial pasture from the years 2010 to 2012 in Isparta Province located in the Mediterranean region of Turkey. The mixture of the pasture used were alfalfa (Medicago sativa L.) + sainfoin (Onobrychis sativa Lam.) + crested wheatgrass (Agropyron cristatum L.) + smooth bromegrass (Bromus inermis L.). Animal grazing applications were performed in the second and the third year of the study since the first year covered only the establishment of the artificial pastures. Forage samples were collected from grazing and non-grazing areas once every 15 days during the grazing seasons. The crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF) contents, total digestible nutrient (TDN) and relative feed value (RFV) were determined on the smooth bromegrass forage samples. According to results, CP, TDN and RFV values decreased throughout the grazing season, while ADF and NDF contents increased in grazing and non-grazing areas. The ADF and NDF contents of smooth bromegrass in non-grazed areas were higher than the grazed areas, while CP, TDN and RFV values of grazed areas were higher than non-grazed areas. It can be concluded that the harvesting at the late stages caused a reduction in forage quality of smooth bromegrass in grazing and non-grazing areas.

Environmental conditions and climate change on a global scale affect the overall agriculture and food supply. Globe artichoke (Cynara cardunculus var. scolymus (L.) Fiori) is widely distributed all over the world. Immature inflorescence, commonly called capitula or head, is used in human consumption. These vegetables are a good source of human health promoting components. Artichokes are widely used in human diet, characterized by low protein and fat, high content of minerals, vitamins, inulin, carbohydrates and polyphenolic compounds. Relationship between plant growth and development is tight and complicated. Many agroecological factors, such as temperature, irrigation and fertilization level, planting and harvesting date, influence processes of growing and development of globe artichoke. Biologically active compounds in plants are dependent on climate conditions, seasonal changes, cultivar properties and maturity. Pre-germination is required for better plant establishment in the field. Better plant growing and development can be ensured by regular irrigation which provides 85 – 100% from evaporation and applied fertilization before planting and during vegetation period according to soil properties. The biochemical quality of artichoke heads differs between cultivars, head fraction, and stage of head development. This indicates possibility to grow artichokes in Latvia.

This study was carried out in 2012 to determine the effects of different irrigation intervals and irrigation water amounts on the cut flower performance of oriental lilium (Lilium L.) ‘Casa Blanca’ cultivated in greenhouse conditions. Different ratios of the plant water consumption (Tr) calculated using exterior radiation values of the greenhouse were applied to the plants as irrigation water. Irrigation water amounts varied between 199.3-589.0 mm, whereas measured plant water consumption (ETa) varied between 314.9-613.8 mm according to the treatments. Different irrigation water amounts and irrigation intervals had statistically significant effects on flower stem length, flower stem diameter, stem weight and number of flowers. In the study the stem length varied between 26.4-74.7 cm, stem weight varied between 72-175 g, stem diameter varied between 5.0-9.5 mm and the number of flowers buds varied between 3.6 and 8.0. The experimental treatment on which about 1.25 times of the potential plant water consumption calculated in two day intervals and the experimental treatment on which about 1.50 times of the potential plant water consumption calculated in four day intervals were selected as irrigation program.

There is an increasing demand in the development of new and better types of organic plant fertilizers. The aim of the present study was to evaluate if the beneficial effect of vermicompost on plant growth and development could be further promoted by adding different amounts of bat guano using two model species under controlled conditions, as well as to assess the microbiological characteristics of bat guano and soil after its application. The study was performed at the Faculty of Biology, University of Latvia, during 2013 and 2014. The amount of bacteria was significantly lower in guano in comparison to vermicompost samples. No actinobacteria were present, but yeasts were found in the guano sample. Soil fungal populations after the application of organic fertilizer from vermicompost and bat guano were dominated by potentially plant growth promoting fungi Trichoderma and Mortierella. However, at increased guano concentration (300 g kg˗1) the proportion of potentially plant pathogenic fungi significantly increased. Addition of bat guano to vermicompost fertilizer significantly enhanced the positive effect of the fertilizer on growth and development of winter rye (Secale cereale L.) and potato (Solanum tuberosum L.) plants.

In automatic milking systems, where the concentrate and forage components of the ration are offered to the cows separately, lack of control over intakes can result in difficulties balancing the forage and concentrate portions of the diet, leading to problems associated with high concentrate intakes and concomitant low forage intakes. In order to check this as a problem on a dairy unit, the feeding behaviour of a sample of cows was observed by video recording. As a pilot study, four Holstein Friesian cows (two at the highest yield and two at the lowest yield of the milk production range) were selected from sixty lactating cows on the Estonian University of Life Sciences’ farm near Tartu, Estonia. The study took place from May 18th till November 4th 2014. The cows were robot-milked and fed a ration comprising, separately, concentrate feed from a robot and a feeder, and a grass/clover silage mix forage at the feed barrier. With the low number of samples the results are indicative and descriptive, but it appears from the raw data that individual variation in visiting times and times spent at the feed barrier are greater than the effect of level of production. Cows spent a significant portion of their time idling at the feed barrier, not actively feeding. It is concluded that care should be taken to presume behaviour from positional data, and there is no evidence that cows with higher and lower milk yields are differentially motivated to feed from a forage source.

The purpose of research was to analyze dairy cows (Bos taurus) milk productivity according to the calving body condition score (BCS) and to predict the nitrogen output with urine according to BCS and live weight. The research was carried out at the Research and Study farm ‘Vecauce’ of Latvia University of Agriculture. Data were collected from 55 dairy cows during October 2013 to October 2014. Dairy cows were from different breeds (Holstein Black and White, red breed cows with Holstein blood more than 40% and crossbreeds) and different lactations. Cows were grouped in two groups for the estimation of BCS effect on the analyzed traits: BCS is less than or equal to 2.5 and BCS is greater than or equal to 2.6. BCS was estimated at calving and in monthly recording control days. Nadir value of BCS is greater than or equal to 2.6 group was 2.64 ± 0.06 points on the third control day, but 2.46 ± 0.08 points of BCS is less than or equal to 2.5 on the second control day. Calving live weight of BCS is less than or equal to 2.5 and BCS is greater than or equal to 2.6 groups were 613.8 ± 13.3 kg and 651.1 ± 11.4 kg. The highest milk yield was observed in BCS is greater than or equal to 2.6 group until the third control day, the highest fat content was observed in this group, but the highest protein content was in BCS is less than or equal to 2.5 group. Milk urea content was not significantly affected by calving BCS, but milk urea content of BCS is greater than or equal to 2.5 group ranged from 23.2 ± 1.86 to 30.9 ± 1.98 mg dLE-1, and from 20.6 ± 1.53 to 30.2 ± 2.27 mg dLE-1 in BCS is greater than or equal to 2.6 group. A significantly higher urinary nitrogen output was observed from BCS is greater than or equal to 2.6 group on the second control day – 237.8 ± 8.1 g dayE-1 (p is less than 0.05).

Potato (Solanum tuberosum L.) is one of the most important agricultural crops for human consumption and high amount is produced worldwide every year. Potato peel waste is a zero value by-product, which occurs in big amounts after industrial potato processing and can range from 15 to 40% of initial product mass, depending on the peeling method. Food waste utilization causes great concern in food industry in Europe and many scientific works were written on this topic in the last years offering solutions and original approaches. Present article aims to summarize the review of available literature on industrial potato peel waste application possibilities in food production industry. Scientific articles on food waste management, potato peel chemical composition and recycling methods have been studied. The main results show, that there is a big potential for potato peel extract as an antioxidant in food systems due to its high phenol content. In addition, potato peel powder could serve as a partial flour replacement in dough up to 10 g 100 gE-1 of flour weight without causing significant changes in sensory properties. Potato peel waste can serve as a solid substrate for fermentation. Further investigations in the present field are needed in order to evaluate full potato peel waste application potential.

Avian mycoplasmosis have been considered a severe problem in poultry diseases; Mycoplasma gallisepticum being one of the most important. This study was conducted in Joint-Stock Company Balticovo, Latvia, to determine the prevalence of M. gallisepticum infection in hen’s flocks in the farm. A total of 904 serum and 335 swab samples from non-vaccinated birds against M. gallisepticum from 65 chicken flocks of different age, from day 1 to 75 weeks old, were all tested. The commercially available enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) tests were used. Results revealed that the seropositive flock rate, based on ELISA tests and, according to ratio that represents the extent to which a light source effectively stimulates the rods: S/P ratios and antibodies titer higher 1.076 were 22/904 (2.43%) and 4/904 (0.44%), respectively, while PCR-positive flock rates were not confirmed. Seroprevalence of M. gallisepticum in commercial layer flock in Latvia was more common seen in birds from 17 to 30 weeks of age.