خيارات البحث
النتائج 1381 - 1390 من 2,098
Post fire ground vegetation development over 25 years
2021
Freimane, L., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Caksa, L., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Karklina, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Elferts, D., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);University of Latvia, Riga (Latvia) | Berzina, B., University of Latvia, Riga (Latvia)
Fire has been a part of natural disturbance regime in boreal and to some extent also hemiboreal forests, affecting soil and light conditions, seedbanks, trees and ground vegetation. The most significant factors affecting occurrence, severity and size of forest fires are anthropogenic, weather and the environment, all of which are changing due to human-caused climate change. This paper discusses medium term (25 years) vegetation development in five different biotopes after fire disturbance. Sample plots were established in Slitere Reserve (now National park) in north-western Latvia on areas affected by large fire in 1992. Data were collected in 1993, 2002 and 2017. The aim of the study was to characterize the regeneration and succession of ground vegetation after the fire. In 1993, species such as bog-rosemary (C) were observed in the ground vegetation a year after the fire. In 2002 liverworts appeared, indicating that the bog has acquired more stable and wetter conditions, but in 2017, liverwort mosses were no longer present and the percentage cover of Rubus chamaemorus decreased significantly and Calluna vulgaris, sphagnum sp., and Betula pendula were present in large quantities in the bog. Comparing these studied years, it can be concluded that all these years the biotopes and species have continuously developed and are regenerating.
اظهر المزيد [+] اقل [-]Research for Rural Development 2019. Annual 25th International Scientific Conference Proceedings (online resource)
2019
In the celebration of the Annual 25th International Scientific Conference “Research for Rural Development 2019ˮ held at the Latvia University of Life Sciences and Technologies, in Jelgava, from 15 to 17 May, participants with different backgrounds from 12 countries did 156 presentations, enjoyed welcome dinner with Latvian folk songs and dances as well as tasted a special cake. During a social programme of the conference, the participants visited a malt production plant, Rundāle palace and had farewell lunch. In the retrospect, four months later, we consider the Conference a great success in terms of interdisciplinary studies and networking opportunities. The sessions of the conference were structured so as to give all participants the opportunity to contribute to the primary purpose of the conference, which is discussion of important current issues facing rural development. The interdisciplinary proceedings of the Annual 25th International Scientific Conference “Research for Rural Development 2019ˮ (two volumes since 2010) are intended for academics, students and professionals. The subjects covered by those issues are as follows: crop production, animal breeding, agricultural engineering, agrarian and regional economics, food sciences, veterinary medicine, forestry, wood processing, water management, environmental engineering, information and communication technologies.
اظهر المزيد [+] اقل [-]Liming effect on nitrogen use efficiency and nitrogen oxide emissions in crop farming
2016
Kreismane, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Naglis-Liepa, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Popluga, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Lenerts, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Rivza, P., Latvia Univ. of Agriculture, Jelgava (Latvia)
Liming soils make both direct and indirect effects on greenhouse gas (GHG) emissions. If raising the pH of soil, the amount of N2 O emissions in the result of nitrification decreases; therefore, it is important to perform also maintenance liming if applying nitrogen fertilisers. Liming acidic soils contributes to the absorption of nutrients supplied by means of fertilisers by plants, limits the spread of plant diseases, forms better soil moisture and air regimes for plants, improves the structure of soil and activates microorganisms. The aim of this study was to assess liming effect on nitrogen use efficiency and nitrogen oxide emissions in crop farming. To achieve the aim, this study proceeds in two stages: 1) to analyse the scientific literature on the liming effect on nitrogen use efficiency and nitrogen oxide emissions in other countries, as a few such research studies are available in Latvia; 2) to calculate potential gains and losses from liming acid soils in order to examine the real situation concerning liming and its effects on the economy of farms. The research finds out that at the farm level in Latvia liming gives a positive economic effect (41.6 EUR haE-1) however, it is essential for maintaining soil fertility, increasing yields, and presumably for more efficient circulation of nitrogen, which decreases nitric oxide emissions.
اظهر المزيد [+] اقل [-]Effect of conformation traits on longevity of dairy cows in Latvia
2016
Cielava, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Paura, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
Cow lifespan is one of most important economical traits in every dairy farm and is affected by different environmental factors. One of genetic factors that affect longevity is cow conformation traits, which varies within different breeds, farms and animals. The aim in this study was to determine how stature and linear conformation traits affect cow lifespan and lifetime milk productivity. In the study, data about 34806 crossbred Holstein Black and White and 38201 Red cow group breed cows, which ended at least one full lactation, and were culled from 2002 – 2012 year were analysed. Data about cow productivity and culling was obtained from Latvian Agricultural Data centre. In the study, data about cow stature, udder depth, central ligament, teat length, and rear and front teat placement were analysed. Conformation traits were distributed in 3 groups. The average lifespan of analysed cows was 1869.9 days in which average 18550.8 kg energy corrected milk (ECM) was obtained. Holstein Black and White cows characterize with shorter lifespan (1833.7 days) than red breed group cows, but lifetime productivity is for 2339.1 kg ECM higher than for average red breed cow. Significantly longer (p is less than 0.05) lifespan – 2031.6 days was in cow group with stature 100 – 135 cm, but in cow group with stature more than 146 cm there is significantly higher lifetime and life day productivity. There is a significant difference between lifetime milk productivity and rear and front teat placement. Significantly higher productivity was given by cows with teat placement inside of quarter (linear evaluation 6- 9 points).
اظهر المزيد [+] اقل [-]Amino acid and dietary fibre content of pea and buckwheat flours
2016
Krumina-Zemture, G., Latvia Univ. of Agriculture, Jelgava (Latvia) | Beitane, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Gramatina, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of this study was to investigate amino acid content, biological value and dietary fibre content of conventional and organic pea (Pisum sativum L.) and buckwheat (Fagopyrum esculentum M.) flours. Results showed that pea flours contained high amounts of aspartic acid, threonine, serine, glycine, alanine, valine, isoleucine, leucine, tyrosine, phenylalanine, histidine, lysine and arginine while glutamic acid, proline, methionine and tryptophan were found in similar or smaller amounts comparing with wheat flour. The differences of various amino acids between conventional and organic pea flours were insignificant. The content of aspartic acid, threonine, serine, glycine, alanine, valine, histidine, lysine and arginine was high in buckwheat flours in comparison with wheat flour. There were significant (p is less than 0.05) differences in the individual amino acid contents across buckwheat flours. Significant (p is less than 0.05) variation existed in the content of essential amino acids among samples, whereas the results concerning the proportion of essential amino acids in total amino acids showed insignificant (p is greater than 0.05) differences between pea flours and buckwheat flours (34.80 – 35.77% and 29.96 – 33.90% respectively). The highest content of lysine was found in pea flours, and it formed about 23% of essential amino acids content. For pea flours the total dietary fibre amount varied between 15.28 g 100 gE-1 for conventional and 27.24 g 100 gE-1 for organic pea flour. Pea and buckwheat flours could be characterised as a good source of dietary fibre with significantly (p is less than 0.05) higher content of total dietary fibre comparing to wheat flour.
اظهر المزيد [+] اقل [-]Characteristics of dry naturally fermented kvass obtained by spray drying
2016
Lidums, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Karklina, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kirse, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Kvass is an aromatic soft drink which in a form of powder could be used in dairy or bakery products, or sugar confectionary to expand the diversity of flavours. Spray drying is one of the techniques used for producing powders; however, liquids with high sugar content become sticky during drying process and need additional drying aids to increase glass transition temperature and improve powder stability. The aim of this research was to evaluate the characteristics of dry naturally fermented kvass. Maltodextrin was used in 50, 40 and 25% quantity to kvass dry matter in order to aid the spray drying of naturally fermented non-pasteurised, non-filtered bread kvass. Spray drying of 8 l naturally fermented kvass returned approximately 500 g dry naturally fermented kvass powder with a light brown colour, a pronounced aroma of rye bread and moisture content of 7 ± 0.1%. Microstructure analysis of the spray dried naturally fermented kvass showed irregularly spherical shaped particles, having many shrinkages, breakages and dents on the surface in general. Total viable microorganism count in dry naturally fermented kvass powder was within the recommended levels, traces of lactic acid bacteria were found in all samples. The presence of Bacillus amyloliquefaciens was established in dry naturally fermented kvass powders, with possible contamination from spray dryer.
اظهر المزيد [+] اقل [-]Fortified chocolate snacks with increased level of iron
2016
Pastore, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Muizniece-Brasava, S., Latvia Univ. of Agriculture, Jelgava (Latvia)
Iron deficiency is a common problem especially among children, women of reproductive age and sportsmen. Addition of highly bioavailable iron to foods could be one possibility to enrich daily diet and increase iron absorption. At present moment, there is a limited number of fortified products with iron in the market. Fortification of common food products is an effective strategy to prevent or overcome iron deficiency. The results show a significant increase of iron in products supplemented with bovine alimentary albumin. Comparing fortified products with non‑fortified control samples of chocolate snacks the iron content increased from (1.17 – 2.61) to (10.15 − 11.53) mg 100 gE-1 in products supplemented with bovine alimentary albumin. By developing a successful recipe of fortified food products, animal origin heme iron could be applicable component and satisfy sensory acceptability from consumers. The aim of this work was to create an alternative sweet product as healthy snack with incorporated highly bioavailable heme iron which may be an addition to daily diet with nutritional properties and accepted by consumers.
اظهر المزيد [+] اقل [-]Effects of antibiotic growth promoters on biochemical and haematological parameters of broiler chickens’ blood
2016
Slyamova, A., Kazakh National Agrarian Univ., Almaty (Kazakhstan) | Sarsembayeva, N., Kazakh National Agrarian Univ., Almaty (Kazakhstan) | Valdovska, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Micinski, J., University of Warmia and Mazury in Olsztyn (Poland) | Ussenbayev, A., Kazakh National Agrarian Univ., Almaty (Kazakhstan) | Paritova, A., Kazakh National Agrarian Univ., Almaty (Kazakhstan) | Mankibayev, A., Kazakh National Agrarian Univ., Almaty (Kazakhstan)
This study was designed with the aim to determine the impact of residual antibiotics on haematological and biochemical constituents of broiler chickens’ blood. For this, one-day-old chickens were randomly divided into four equal groups with 10 individuals in each group (n = 40). All groups of chickens fed with commercial basal diet; the first group considered as control, fed only with basal ration; the feed of the second, third and fourth groups of chicken were supplemented with amoxystin, tetracycline and chloramphenicol, respectively. Antibiotics were given daily, individually, in sub-therapeutic concentrations: amoxystin at the dosage 10 mg kgE-1, tetracycline and chloramphenicol – 20 mg kgE-1 of the chicken’s weight for 41 days. The blood parameters were measured at the end of experiment on the 42nd day. In comparison with the control group, decreasing of leukocytes was observed in the 2nd and 4th groups, and increasing in the 3rd group of broilers. The concentration of erythrocytes and hemoglobin was reduced in the 2nd group and hematocrit was higher in the 3rd and 4th groups (p is less than or equal 0.01). The total protein was decreased by 22% in the 2nd group, 16% – in the 3rd and 4th groups as compared to the control group (p is less than or equal 0.01) in blood serum. The concentration of glucose was decreased by 45.8, 46.5 and 51.5% in the second, third and fourth groups of treated birds, respectively, compared to those of birds in the control group (p is less than or equal 0.01). Based on the results it could be concluded that antibiotics influence the dynamics of haematopoiesis and biochemical indices of broilers.
اظهر المزيد [+] اقل [-]Computed tomography findings of dogs with medial coronoid disease
2016
Veksins, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kozinda, O., Latvia Univ. of Agriculture, Jelgava (Latvia)
Canine elbow dysplasia is an heritable orthopaedic disease which includes medial coronoid disease, osteochondritis dissecans and ununited anconeal process, as well as, elbow incongruity. Medial coronoid disease (MCD) is one of the most frequent parts of elbow dysplasia syndrome. The aim of the study was to describe medial coronoid process CT findings in dogs with thoracic limb lameness. In cases where there is suspicion of medial coronoid disease for dogs with lameness, an orthopaedic examination and CT were performed. CT examination was done with Philips MX-16 – slice CT scanner. The study represents data from a time frame between September 2014 and December 2015. Examinations were done at The Faculty of Veterinary Medicine, Latvia University of Agriculture. The study included 20 large breed dogs, 14 males and 6 females, ages ranging from 6 to 60 months, with a median age of 21.7 ± 13.7 months. Results showed that, in most cases, the dogs had subtrochlear sclerosis of the ulna and fragmentation of medial coronoid. Computed tomography revealed 12 dogs with medial coronoid disease in both elbows, whereas 8 dogs only in one of the elbow joints.
اظهر المزيد [+] اقل [-]Analysis of purposes of use of real property in municipalities of Latvia
2016
Kukule, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Baumane, V., Latvia Univ. of Agriculture, Jelgava (Latvia)
One of the cornerstones of sustainable use of land resources is the use of land resources for the identified needs. In every country it is needed to list the land according to the type of land use. Such function of land classification in Latvia is maintained by the classification of purpose of real property use. In a certain period of time needs of the specific purposes for which the land resources are used are changing, so the aim of this study is to research changes of areas of purpose of real property use in municipalities of Latvia. The analysis of purpose of use of real property in Latvia municipalities demonstrates the trend of decrease of agricultural land resource areas in proportion to the increase of forest land resource areas, excluding the region around Riga, where areas of agricultural land and forest land resources are decreasing, but residential land resource area for needs of development of capital is increasing.
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