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Physical-chemical evaluation of sous vide cooked parent stock hen breast meat during refrigerated storage
2010
Ramane, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Galoburda, R., Latvia Univ. of Agriculture, Jelgava (Latvia) | Murniece, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dukalska, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of this study was to evaluate physical and chemical changes in sous vide cooked marinated parent stock hen breast meat during refrigerated storage. Sous vide method is suitable for preparation of ready-to-eat meat products satisfying consumer demand for convenience and safety. Meat tenderness is recognized as important quality attribute of meats. The study involved preparation of the raw material, vacuum packaging of the products in polyamide/polyethylene (PA/PE) film pouches, marinating for 20 hours, sous vide cooking and chilling in ice water, followed by storage at 3.0±0.5 deg C. Each sample containing a chicken portion or chicken mix with shredded carrots, sea buckthorn sauce and spices was analysed during storage. Water activity, pH, and moisture were assessed during storage. Hardness (shear force) measurement was used as an instrumental method for meat tenderness evaluation. The differences between two studied products were noted regarding all studied parameters – water activity, pH, moisture content, and hardness. The differences mainly were determined by the properties of carrot and sea buckthorn additive, which generally have higher moisture content and lower pH. The researched parameters were well preserved during refrigerated storage for 28 days.
显示更多 [+] 显示较少 [-]Grey alder fibreboard processed by modified steam explosion unit
2010
Tupciauskas, R., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvian State Inst. of Wood Chemistry, Riga (Latvia) | Gravitis, J., Latvian State Inst. of Wood Chemistry, Riga (Latvia) | Belkova, L., Latvian State Inst. of Wood Chemistry, Riga (Latvia) | Tuherm, H., Latvia Univ. of Agriculture, Jelgava (Latvia)
Experimental self-binding high-density fibreboard is produced of the grey alder (Alnus incana L. Moench) steam-exploded fibres without addition of synthetic adhesives. Milled grey alder chips are processed in steam-explosion unit by saturated steam under pressure of 3.2 MPa at temperature of 235 deg C for 1 min in a 0.5 l batch reactor. The steam-exploded fibres are pressed at 160 deg C temperature under 8 MPa pressure for 10 min in three steps. Properties, such as density, swelling in thickness, water absorption, bending strength, modulus of elasticity at bending, and internal bonding strength of the studied fibreboard samples are reported. Differences between the raw milled chippings and the exploded fibres are observed by scanning electron microscope. The study is focused on modified technical options of the steam-explosion unit supplied with two containers receiving different kinds of the exploded biomass farther used to obtain the hot-pressed boards. The cascade of the receivers is explained in a presently pending patent. The self-binding high-density fibreboard samples show the following properties comparable to commercial products: density of at least 1.35 g cmE-3, moisture content of 7.2%, swelling in thickness of 8.1%, water absorption of 3.2%, bending strength of 27 N mmE-2, modulus of elasticity of 6,259 N mmE-2, and internal bonding of 0.92 N mmE-2.
显示更多 [+] 显示较少 [-]Results of black alder (Alnus glutinosa (L.) Gaertn.) improvement in Latvia
2010
Gailis, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Jansons, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Black alder wood is suitable for production of high quality veneer and other uses, but doe to its small share in total forest area (3%) in Latvia its genetic improvement have not been a priority. Set of progeny tests, together 22.8 ha, have been established only in the last decade. First of them have reached the age of 8 to 10 years and are suitable for first assessment. Aim of our study was to evaluate potential of improvement of black alder using selection, based on progeny testing. Data from 4 open pollinated progeny tests of phenotypically selected black alder plus trees, located in central part of Latvia, each containing from 15 to 21 families, are evaluated, using breeding value as a criterion. Results reveal that selection of parent trees with the practically possible intensity (10%) yields notable improvement in height at the age of 8 to 10 years: from 10 to 32%. Parent trees of open-pollinated families S9, S14, S16 and 84115 that have superior productivity and above-average quality can be recommended for establishment of second-round seed orchard. Estimates of genetic parameter suggest that selection in black alder trials could be carried out with high accuracy and improvements are possible both in productivity and quality (branch thickness, stem straightness, occurrence of spike knots).
显示更多 [+] 显示较少 [-]Postpartum serum biochemical and haematological changes in cows with and without retained foetal membranes
2010
Skuja, S., Latvia Univ. of Agriculture, Jelgava (Latvia) | Antane, V., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the study was to find out the differences of blood biochemical and morphological parameters in cows with and without retained foetal membranes. Sixty cows of different age of Latvian blackand- white breed from two Joint Stock Companies were used in the research that was divided into two groups: control group of 15 cows, and 45 cows with retained foetal membranes. Research was done from September 2007 to January 2009. In haematological parameters on the second day postpartum, control group cows had increased leukocyte count on the account of mature neutrophils, but in the group of cows with retained foetal membranes leukocytes were within the range of normal values. The difference of the above mentioned parameters between both of the groups was significant (p is less than 0.05). At the same time, in cows of both investigated groups the number of band neutrophils was slightly increased (p is greater than 0.05). Haematological analyses showed leukocytes shift to the left and lymphopenia with a tendency to get normal within six weeks postpartum in both cow groups. On the third week postpartum, in cows with retained foetal membranes the band neutrophil count increased significantly (p is less than 0.05) indicating that the inflammation process has flared up. Blood for biochemical examination was sampled from cows within 48 hours postpartum in order to evaluate the functional condition of liver in milking cows. A significantly higher (p is less than 0.05) total and direct reacting bilirubin was observed in cows with retained foetal membranes, although it was within the range of normal values.
显示更多 [+] 显示较少 [-]Intrauterine fluid secretion in mares after artificial insemination
2010
Liepina, E., Latvia Univ. of Agriculture, Jelgava (Latvia) | Antane, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Rivera del Alamo, M.M., Autonomous Univ. of Barcelona (Spain)
Reduced fertility associated with fluid accumulation has been recognized for many years in broodmares. Fluid present in the uterus after ovulation is often associated with mare susceptibility to endometritis. Objective of this study was to determine amount of intrauterine fluid secretion and endometrial oedema in mares at the time of artificial insemination (AI), 6 h, 25 h, and 48 h after AI and at the time of ovulation. A total of 22 cycling light breed mares from MTT Agrifood Research, Ypaja, Finland, were used in the study. Relaxation of the cervix, the number and size of follicles, corpus luteum, and the degree of endometrial oedema were examined by transrectal palpation and ultrasonography every other day. According to the closing and opening time of the cervix which was regulated using Bivona catheter, mares were distributed into 3groups. Group A (n=7): immediately after artificial insemination (AI) the catheter was inserted into the uterus. After 25 h, the catheter was opened and the fluid drained. Group B (n=8): immediately after AI, Bivona catheter was inserted into the uterus. After 6 h and 25 h the catheter was opened and the fluid drained. Group C (n=7)-control group: no catheter was inserted into the uterus. According to our investigation, we concluded that the amount of intrauterine fluid accumulation (IUFA) in mares increased within 25 h after AI. Mares with delayed uterine clearance had a significantly larger amount of intrauterine fluid than mares with normal uterine clearance. Open cervix during oestrus period is important for adequate clearance of intrauterine fluid in mares. Opening of intrauterine catheter at 6 h post AI didn’t diminish intrauterine fluid accumulation at 25 h post AI.
显示更多 [+] 显示较少 [-]Perinatal ontogenesis of gastric mucosa in the ostrich (Struthio camelus var. domesticus)
2010
Duritis, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Mugurevics, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
There are several unique features in the anatomy of the stomach in African ostrich in comparison with other birds. The goal of this study was to determine changes in the main morphometric parameters and histological features of gastric mucosa in ostrich chickens from the 38th day of embryonal development until 60 days of age. For the study, 6 embryos (38th day of development) and 36 chicks (1, 3, 7, 14, 30, and 60 days post hatching; 6 chicks per time point) of both sexes were obtained from African ostrich farm in Latvia during May - October, 2009. Tissue samples were investigated in Preclinical Department, Faculty of Veterinary Medicine. The total area of proventricular mucosa (cm2) and surface area of deep glands (cm2) was measured. Tissue sections for histological assessment were stained with: hematoxylin and eosin and alcian-blue pH 2.5 - periodic acid – Schiff reaction. Thickness of proventricular and ventricular mucosa, depth of proventricular superficial glands as well as surface area of parenchyma occupied by deep glands were measured in histologic sections. As the chick age increased, there were changes in the ratio of areas occupied by proventricular superficial and deep glands with relative decrease in area occupied by deep glands. Proventricular deep glands developed rapidly after hatching; at the age of 30 days deep glands histologically resembled glandular structure of adult birds. Gastric mucosal epithelial cells of 38 days old ostrich embryos and of just hatched ostrich chicks contained neutral, acidic, and mixed mucopolysaccharides. Meanwhile, in the pyloric region of ventriculus acidic mucopolysaccharides predominated.
显示更多 [+] 显示较少 [-]Enumeration of Listeria monocytogenes in different ripening stages of cold smoked sausages
2010
Silins, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Liepins, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
The non-spore forming gram-positive bacterium Listeria monocytogenes is a food pathogen bacterium and the causative agent of listeriosis. The aim of study was to determine the survival limits of L. monocytogenes inoculated in manufactured cold smoked sausages depending on water activity (aw) and pH values. Enumeration of L. monocytogenes colony forming units per gram (cfu gE-1) was done according to ISO standards. The decreasing water activity conditioned by moisture (weight) loss during ripening and pH decrease ensured negative exponential growth rate of inoculated L. monocytogenes lg cfu gE-1 - 0.44 each day. A significant Pearson's correlation (p is less than 0.01) was established between decreased values of L. monocytogenes count, aw (0.99), pH (0.92), moisture % (0.96), and weight loss (0.93) in sausages during ripening. The experiments were done at the Faculty of Veterinary medicine of the Latvia University of Agriculture and in a sausage manufacturer's laboratory.
显示更多 [+] 显示较少 [-]Comparative study of breeding bulls daughters milk quality indicators
2010
Dujina, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jemeljanovs, A., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvia Univ. of Agriculture, Sigulda (Latvia). Research Inst. of Biotechnology and Veterinary Medicine Sigra | Konosonoka, I.H., Latvia Univ. of Agriculture, Sigulda (Latvia). Research Inst. of Biotechnology and Veterinary Medicine Sigra
The aim of the work is to investigate raw milk from different bulls' daughters to clear up the influence of cows' genetic predisposition to milk microbial contamination and somatic cell count (SCC). Particular attention is paid to develop productive cow milk yield, milk fat, milk protein and in recent years, the SCC heredity. The literature describes a variety of lines and families, representatives of the resistance to certain diseases (leucosis, mastitis, tuberculosis, brucellosis, foot disease), it shows the determination of a genetic factor for this trait. If the selection results show increased resistance to a disease, then this indicates a genetic disease resistance and shy. The paper focuses on microbial contamination of raw milk at 7 different studies of bull daughters in the same line for housing, feeding and conditions of use. Raw milk samples were obtained from the breed Latvian brown (LB) from dairy cows shed of cattle shed Saujas, which belongs to SIA Palsa and is located in the civil parish Varini, Smiltene county in the year 2008/2009. Compared between the lines of bulls' daughter milk yield of the sample average value of the uniformity of variance analysis shows that they significantly differ (F=2.452, p=0.039). Comparing each line of bulls' daughters SCC of the sample average value of the uniformity of variance analysis showed that the SCC was statistically significantly different (F=2.083, p=0.075) of the various lines of bulls daughters.
显示更多 [+] 显示较少 [-]Identification and application possibilities of tourism system models in regions
2010
Kaufmane, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
Systemic view on tourism as an economic activity is the best way how to characterise an economic nature of this industry. The paper presents the methodology which integrates the system approach and other research methods of social sciences; this methodology forms the basis for identification of social agents and models of tourism system. The methodology is approbated in the survey of providers of rural tourism services in Zemgale planning region. The research results are useful in future application of models for development of tourism whereas the models are useful for other purposes: they can provide additional information necessary for evaluation of tourism influence on economy. They form a basis for detecting participants in tourism clusters in regions and for evaluation of cooperation between social agents of public, nongovernmental and private sectors, and as an instrument in tourism marketing strategies.
显示更多 [+] 显示较少 [-]Competition legislation framework of dairy sector integration in the Baltic States
2010
Ozolins, J., Latvia Univ. of Agriculture, Jelgava (Latvia)
Appropriate resources, availability of infrastructure, economic significance and food market forecasts determine the rationale for development of the dairy sector in the Baltic States. The sector is faced by significant economic problems; inter alia, production structure fragmentation, lack of investments and low labour productivity. Several sector's problems can be directly or indirectly solved by integration. Competition legal acts setting strict penalties directly and widely apply to integration processes, imposing a high level of legal risks on integrating parties. Thus, competition legislation forms a central framework limiting and guiding integration. As the subject has not been explored earlier, the author researched the Baltic dairy sector integration options at primary and secondary levels as influenced by the EU and Baltic national competition legislation and its implementation practice. Abstract-logical, monographic and interview methods have been used. The author concludes that law-compliant cross-border integration opportunities for the Baltic dairy sector exist to form larger integrated undertakings with higher market power. Reference to market shares in the competition legislation in countries with lower aggregate crude milk market sales puts the dairy sector participants at a disadvantage in case of integration processes resulting in smaller absolute size of the allowable integrated undertaking. Integration by agreements, decisions and concerted practices is appropriate for national level arrangements but is with limited applicability in the Baltic states cross-border integration at both levels of the dairy sector. In case of concentration, integration may be used to create cross-border integrated structures increasing concentration at every level of the Baltic dairy sector.
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