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The abandoned block-cut peat extraction field influence on the natural raised bog hydrological regime Full text
2016
Purmalis, O., University of Latvia, Riga (Latvia);Institute for Environmental Solutions, Riga (Latvia) | Grinfelde, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Valujeva, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Burlakovs, J., University of Latvia, Riga (Latvia);Linnaeus Univ. (Sweden). Faculty of Health and Life Sciences
Peat is still mined in many parts of the world for production of peat substrates and energy. Many peatlands were affected by drainage in the past also for forestry and agricultural needs. Nowadays a raised attention to peatlands is focused, especially to drained peatlands due to their carbon reserves and their potential influence to the climate on the one hand, but on the other hand - due to raising awareness on protection of environment, habitats and biotopes. There are many examples on restoration activities in peatlands found worldwide, especially their water regime is the subject of regulation, which plays the major role to bring back original functions. In most cases in Latvia as the aim for protection and restoration of degraded peatlands was protection of EU biotopes and habitats. Of course, peatlands play an important role in emissions of the greenhouse gases CO2, CH4 and N2O, produced during mineralization of the drained peat organic matter. In literature, we can find only few cases where hydrological regimes are described for natural raised as well as restored block-cut peat extraction fields. This research analyses block-cut peat extraction field water level fluctuation influence on naturally raised bog hydrological regimes. Hourly data is analysed for six groundwater monitoring wells as well as for determination needs of water level fluctuations in excavated peat quarry as a response to precipitation.
Show more [+] Less [-]Weather impact on the household electric energy consumption Full text
2016
Jakusenoks, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Laizans, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the article is to ascertain the interaction between weather conditions and electric energy consumption in the Latvia household. The electric energy consumption data in the Saurieši village, Riga region, Latvia, for the year 2012 were collected, and the climate data for the same period including the duration of the sun-shine, ambient air temperature, precipitation intensity, and wind speed were obtained. The research hypothesis that there is strong relation between weather conditions and electric energy consumption was proved partially – there is rather strong correlation between household electric energy consumption and air temperature (r = 0.91), and medium correlation between household electric energy consumption and precipitation (r = 0.61), as well as between household electric energy consumption and duration of the sunshine (r = 0.67). Correlation found between weather conditions and electric energy consumption in the household allows to forecast the trends in energy consumption based on weather measurements, and even to use the weather forecasts for electric energy future demand trends development. The equations developed explain the household energy consumption patterns in Latvia with its geographical location and economic conditions, but the methodology developed can be applied for any region if necessary data are available.
Show more [+] Less [-]Cereal variety mixtures and populations for sustainable agriculture: a review Full text
2016
Locmele, I., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvia Univ. of Agriculture, Priekuli, Priekuli parish, Priekuli Municipality (Latvia). Inst. of Agricultural Resources and Economics | Legzdina, L., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvia Univ. of Agriculture, Priekuli, Priekuli parish, Priekuli Municipality (Latvia). Inst. of Agricultural Resources and Economics | Gaile, Z., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kronberga, A., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvia Univ. of Agriculture, Priekuli, Priekuli parish, Priekuli Municipality (Latvia). Inst. of Agricultural Resources and Economics
Modern varieties developed under conventional plant breeding programs do not always perform well under organic and low-input growing conditions. Therefore, organic farmers need varieties adapted to variable environmental conditions. This means emphasis on traits such as nutrient uptake and use efficiency, good weed suppression ability and disease resistance and can be achieved via extended genetic diversity within the varieties: variety mixtures and populations of self-pollinating crops. The aim of the present study was to review published scientific literature about importance and research results on this topic. Scientific articles about the necessity of such studies and results of investigations performed in different countries have been studied. The main results show that variety mixtures have advantages in terms of disease control and yield stabilization and performance of mixtures may be affected by various factors – choice of components and its number, interactions between plants of components, manner of the mixing and growing technology. Depending on parental material, populations contain greater genetic diversity than variety mixtures. There are trends observed in the studies that yield of populations increased over generations and they are more stable than modern varieties, but there is no evidence that they would be significantly more productive. This research direction has recently become topical and is not sufficiently widely covered in the world agricultural science. The obtained results are inconsistent.
Show more [+] Less [-]Comparison of conformation trait scores of dams and daughters in Latvian warmblood horse breed Full text
2016
Orbidane, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
The objective of the study was to detect the difference of the conformation scores between dams and daughters in Latvian Warmblood horse breed. For this purpose the correlations and regression coefficient between conformation traits of broodmares and the same traits of their daughters were estimated. Data of Latvian Warmblood horse breed broodmares were analyzed. The horse breeding organisations’ evaluating data from 1995 till 2015 were analyzed. The data included conformation valuation of Latvian Warmblood horse breed dams (n = 423) and their daughters (n = 596) of different ages. An average in ten-point scale in the group of dams was 7.71 ± 0.04 for top line scoring, 7.33 ± 0.05 for forelimbs and 7.35 ± 0.05 points for hind limbs. An average of valuation points of their daughters was 7.51 ± 0.03 for top line scoring, 7.21 ± 0.04 for forelimbs and 7.21 ± 0.04 for hind limbs. A significant difference between valuations of dams and their daughters (p0.05) was found for all three conformation traits. Positive and low correlation was calculated between groups of dams and daughters for all three conformation traits. The results show that the relationship between conformation traits of dams and daughters was weak. Further studies are needed in order to estimate influence of broodmare quality to daughters, analyzing the latest data of progeny.
Show more [+] Less [-]Liveweight change of red deer (Cervus elaphus L.) calves after weaning Full text
2016
Parfianovics, M., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kairisa, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
The article analyses the data obtained while evaluating red deer calves on the red deer breeding farm ‘Dumpji’ during the herd’s annual prophylactic check-up in December and April of the years 2013 and 2014. Farm is a private enterprise owned by a company located in Northern Latvia. The study comprises data for calves born in 2013 (n = 36) that were born from the same hinds, but from different stags in consecutive years. It was discovered that the calves’ liveweight gain in 24 hours significantly decreases during wintering period. After the wintering smaller body mass was observed in calves of both sexes born in 2014; however, the body mass of bull calves born in both years of reference considerably exceeded that of the hind calves. In the group of hind calves born in both years of the study period the liveweight loss was observed during the wintering. Nevertheless, at the age of 1.5 years the lowest liveweight among hind calves was 82.4 kg (year 2013), and the highest 129.6 kg (year 2014). In the group of spikers, during the winter period liveweight loss was not observed. Analysis of the results revealed a close positive correlation between the liveweight in December and the liveweight in the spring among spikers and heifers alike. The conducted analysis of influencing factors attests to the fact that the liveweight at the age of six months has material impact on the animals’ liveweight both in the spring and at the age of 1.5 years.
Show more [+] Less [-]High-pressure processing as novel technology in dairy industry: a review Full text
2016
Liepa, M., Latvia Univ. of Agriculture, Jelgava (Latvia) | Zagorska, J., Latvia Univ. of Agriculture, Jelgava (Latvia) | Galoburda, R., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of this review was to summarize available bibliography on the possible applications of high pressure processing in dairy industry, the effect of this non-thermal treatment on bacterial microflora and milk constituents. Traditional thermal treatments applied to milk processing lower nutritional quality because many nutrients are heat labile. To overcome this problem, several non-thermal processing technologies including high hydrostatic pressure (HHP) processing have been developed. Pressures between 400 and 600 MPa inactivate microorganisms including food-borne pathogens; however, high pressure (HP) injured bacteria in milk during storage can recover. All enzymes are inactivated only at pressures of 800 MPa. During HHP the casein micelle size decreases, whey proteins are denaturated, the level of free fatty acids increases. These characteristics indicate that for better understanding and application of HPP in dairy industry research should be done to offer the numerous practical applications to produce microbially safe, minimally processed dairy products with improved performances, and to develop novel dairy products of high nutritional and sensory quality and increased shelf life.
Show more [+] Less [-]Effects of germination on chemical composition of hull-less spring cereals Full text
2016
Senhofa, S., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kince, T., Latvia Univ. of Agriculture, Jelgava (Latvia) | Galoburda, R., Latvia Univ. of Agriculture, Jelgava (Latvia) | Cinkmanis, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sabovics, M., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sturite, I., Norwegian Inst. for Agricultural and Environmental Research (Bioforsk), Tjøtta (Norway)
The objective of the current research was to investigate effects of germination on chemical composition of hull-less barley (Hordeum vulgare L. var. nudum Hook. f.), hull-less oat (Avena sativa), rye (Secale spp.), and wheat (Triticum spp.) grains for comparison. All the grains were cleaned, washed, steeped and germinated at temperature 35 ± 2 °C and relative humidity 95 ± 2% for 12, 24, 36, and 48 hours. After germination grains were dried till moisture content 14 ± 2%. Main quality parameters such as starch, proteins, b-glucan (in hull-less barley) and individual sugars were determined in cereals during their steeping and germination. Non-germinated grains were used as a control sample. In the present experiments non-significant protein content increase was observed in the analysed hull-less barley, hull-less oat, rye, and wheat during their germination for 48 hours. Starch content in hull-less barley, wheat and rye grains decreased non-significantly during germination for 24 h; opposite results were obtained for hull-less oat grains, where content of starch decreased by 16.7% after steeping and by 26.4% after germination for 24 h. b-glucan content in hull-less barley grains after germination for 48 h decreased by 20.5%. Non-significant changes were obtained in fructose content in analysed cereal grains during germination for 48 h; it was significantly increased after germination for 24 h and in germination for 48 h. Non-significant sucrose content changes were observed in hull-less barley, rye and wheat grains during germination for 12 h and in hull-less oat grains – for 24 h significantly increasing in future germination for 48 h.
Show more [+] Less [-]The effect of sea buckthorn (Hippophae rhamnoides) extract on cryptosporidium spp. invasion in calves Full text
2016
Derbakova, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Keidane, D, Latvia Univ. of Agriculture, Jelgava (Latvia) | Liepa, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Zolnere, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
The present work aimed to evaluate the effect of sea buckthorn (Hippophae rhamnoides) extract on Cryptosporidium spp. invasion in calves. Sea buckthorn is a good source of vitamins, carotenoids, organic acids and tannins. It has been reported that it possesses anti-inflammatory effect, as well as anthelmintic and antibacterial activity. Research was conducted in a dairy cattle farm ‘Mežacīruļi’ during April and July 2015. Experimental (n = 10) and control (n = 10) groups of calves were used. The experimental group received a mix of aqueous alcohol sea buckthorn leaf and berry pomace extract, administered with milk, at dose of 5 – 8 mL twice a day for 20 days. The control group received only milk. Samples were analysed with the concentration McMaster technique. The results showed that there is no significant (p is greater than 0.05) difference in the number of oocysts per gram of faeces between the experimental and control groups. It was concluded that the administration of sea buckthorn leaf and berry pomace extract had no effect on Cryptosporidium spp. invasion in calves. Studies will be continued with a higher dose of extract.
Show more [+] Less [-]The changes in Kaunas urban landscape during the period between 2010 and 2015 Full text
2016
Ivaviciute, G,, Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania);Kaunas Forestry and Environmental Engineering Univ. of Applied Sciences (Lithuania);Klaipeda State Univ. of Applied Sciences (Lithuania)
The paper presents the comparative analysis of the Kaunas city landscape change during the period between 2010 and 2015. For this analysis, the land fund statistics of the Republic of Lithuania, which had been grouped into a relatively natural and anthropogenic landscape, were used. Landscape change is graphically shown in the figures. Lithuanian and foreign scientific literature and legal acts as well as planning documents were analysed for the fulfilment of the work. The Kaunas city landscape analysis of the current situation was done. During the analysis the Kaunas city statistics were compared with the data of Kaunas County and the Republic of Lithuania. The analysis showed that during the analysed period the Kaunas city natural landscape area relatively increased by 1115.34 ha or 20.42 percent. The largest part of relatively natural landscape consisted of forests – 51.12 percent. During the period between 2010 and 2015, the anthropogenic environmental area increased by 47.33 hectares (2.80 percent.). In the period between the years 2010 and 2015, the Kaunas city anthropogenic landscape decreased by 1.189.41 hectares or 12.23 percent. This phenomenon was affected by the decrease of built-up areas of 1,233.36 hectares, or 14.10 percent. Built-up areas cover the largest part of the Kaunas city anthropogenic landscape – 88.09 percent. The analysis of the planning documents showed that after their implementation the built-up areas would increase, the aesthetic image of recreational environment would improve, the environmental condition would become of a higher quality.
Show more [+] Less [-]Significance of factors affecting creep development in timber beams Full text
2016
Brokans, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ozola, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
This study is a part of an extensive research of creep development in softwood (Pinus sylvestris) timber beams under natural environmental conditions. Large size test data sample obtained during long-term (approximately one and half year) static loading of timber beams in a four-point bending simulating the real service conditions of roof structures for winter and non-snow period has been processed and results presented. The correlation between creep deformation and its affecting factors, such as span to height ratio of beam, percent of latewood and width of year ring (a growth ring formed during a single year), orientation of year ring segments against main axis of cross section, number of year rings in 1 cm of wood, and density of wood have been analysed and corresponding coefficients of correlation presented. It is concluded that the most significant creep development affecting factor is density of wood. Strong relationship between creep development and width of year ring, number of year rings in 1 cm of wood and density of wood was observed during test. Orientation of year ring segments against the main axis of cross section, amount of latewood and span/depth ratio do not have noteworthy direct influence on creep development in terms of this study. Temperature can be neglected as creep affecting factor in terms of this study but in the moments of sharp raise or fall of temperature, almost immediate effect on creep development was recorded.
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