Pollinators of Helleborus niger in Slovenian naturally occuring populationsAndrej Šušek
, Anton Ivančič
, 2006, izvirni znanstveni članek
Opis: The study is based on documentation and analysis of the major visitors and pollinators of the Christmas rose (Helleborus niger L.) flowers in Slovenian naturally occurring populations. The emphasis was put on 5 groups of insects: bees, bumblebees, large flies, small dipterous flies and pollinators of minor importance. Systematic observations took place in March 2003, at two different locations: on the valley of Bohinjska Bela and on the Peca Mountain. The first location was not far from a rural area, while the second one was in an isolated area, completely in the wild. The analysis of insect activity showed that there were obvious differences in frequency of visits among the insect groups investigated, locations and time of day. In the population of Bohinjska Bela, bees were the most important pollinators, with the highest activity occurred between 10 a.m. and 11 a.m. In the isolated population in Peca the most frequent visitors were small dipterous flies. The study suggests that the Christmas rose is probably an entomophylous (the most important pollinators are insects, such as bees and flies) and predominantly cross-pollinating species. The entomophylous nature appears to be closely associated with the specific botanic characteristics of flowers. Another pollinating agent is probably wind.
Ključne besede: chrismas rose, helleborus niger, wild populations, pollinators, open pollination, cross pollination, population dynamics, plant population
Objavljeno: 13.07.2017; Ogledov: 91; Prenosov: 2
Celotno besedilo (224,24 KB)
Green mathematics: benefits of including biological variation in your data analysisLeopold Tijskens
, Rob Schouten
, Tatjana Unuk
, Marjan Simčič
, 2015, izvirni znanstveni članek
Opis: Biological variation is omnipresent in nature. It contains useful information that is neglected by the usually applied statistical procedures. To extract this information special procedures have to be applied. Biological variation is seen in properties (e.g. size, colour, firmness), but the underlying issue is almost always to the variation in development or maturity in a batch of individuals generated by small scale environmental differences.
The principles of assessing biological variation in batches of individuals are explained without putting emphasis on mathematical details. Obtained explained parts increase from about 60 to 80 % for the usual approach to 95 when the biological variation is taken into account. When technical variation or measuring error is small even 99 % can be achieved. The benefit of the presented technology is highlighted based on a number of already published studies covering the colour of apples during growth and storage and the firmness of cut tomatoes during storage.
Ključne besede: biological variation, biological shift factor, mixed effects nonlinear regression, indexed nonlinear regression, colour of apples, firmness of tomatoes
Objavljeno: 13.07.2017; Ogledov: 75; Prenosov: 2
Celotno besedilo (852,55 KB)
Carcass and meat quality traits of pig fatteners from Slovenian breeding programmeMaja Prevolnik
, Martin Škrlep
, Dejan Škorjanc
, Marjeta Čandek-Potokar
, 2008, objavljeni znanstveni prispevek na konferenci
Opis: The aim of the present study was the comparison of carcass and meat quality traits of commercial pigs of various crossbreeds from two major Slovenian herds. The analysis is based on phenotypic data from field trials which have been collected in the last past five years within the Slovenian breeding programme. Important differences in carcass traits were observed between two herds and were associated to different crossbreeds used. In spite of that economically important result on the slaughter line (lean meat %) was similar for both herds. Meat quality traits were also significantly different between the two herds. Again, the difference could be ascribed to crossbreeds used. However, since the herd effect is connected with abattoir effect, different ante-mortem conditions and/or lower robustness of these animals to premortal stress could also be contributed to the observed differences. The presented results give important information on the state-of-the-art regarding meat quality of Slovenian pigs.
Ključne besede: pigs, carcass quality, meat, breeding programs, Slovenia
Objavljeno: 13.07.2017; Ogledov: 97; Prenosov: 3
Celotno besedilo (140,96 KB)
Techniques of measuring heart rate in cattleMarjan Janžekovič
, Bogomir Muršec
, Ignac Janžekovič
, 2006, izvirni znanstveni članek
Opis: The intensive animal breeding systems can cause severe environment degradation. However, the highly productive animals are extremely sensitive to the environmental changes. The animal welfare can be in direct contradiction with the need for highly intensive and economically successful milk production. The research is aimed at complementing the method of establishing the stress in calves, race heifers, fattened cattle and milk-cows with different body masses. Measuring of heart rate is one of painless measurements of physiological parameters of stress and, from the point of view of animals it has many advantages over the measurements including taking of blood samples. For measuring the heart rate of different categories of cattle without interference into their body we have tested the usefulness of special apparatuses used worldwide by top sportsmen during training for following up, measuring and monitoring the heart rate. These are Polar monitors of the heart rate, made by Finnish company Polar Electro Oy and working wirelessly with ECG precision. The receiver counts the heart rate on the basis of pulse-to-pulse time average algorithms in 5, 15 or 60-second intervals. The computer interface ensures magnetic transfer of measured and saved data on animals into a PC where the analysis of each collected data file follows. The used type of transmitter "Polar sport tester profi" having two electrodes in an air-tight sealed frame has enabled us to obtain a good signal on calves of up to 180 kg body mass. Periodic response in case of young cattle of up to 280 kg body mass has been registered only if electrolyte was added between the animal skin and the feeler. By further modifications and tests of the mentioned apparatuses the expected response has been reached also on adult animals. We found that use of these apparatuses on animals did not have any influence on special animal acting behaviour. The production of milk and meat in herds did not change during the test.
Ključne besede: Polar monitors, modified apparatus, heart rate, cattle, measuring
Objavljeno: 12.07.2017; Ogledov: 68; Prenosov: 2
Celotno besedilo (4,97 MB)
Building of mini digester for mesophilic anaerobic digestionBogomir Muršec
, Peter Vindiš
, 2009, strokovni članek
Opis: Anaerobic digestion is the biological degradation of organic material in the absence of air andmayimply environmental benefits with regard to waste treatment, pollution reduction, energy production, and improvements in agricultural practices. Ananaerobic digester is a system that harnesses this natural process to treat waste, produce biogas that can be converted to heat and electricity and anaerobic digestate, a soil improving material. The paper presents the building of a mini digester for mesophilic anaerobic digestion.With the mini digester the amount of biogas production (methane) from different organic wastes is observed. The basic structure is made of stainless steel, on which other components are fixed. The most important components are the eudiometers, pump and heater with thermostat, fermenters, thermometer and barometer. The experiment is made according to DIN 38 414, part 8. After building of a mini digester some experiments with different organic materials are made.
Ključne besede: mini digester, mesophilic anaerobic digestion, organic wastes
Objavljeno: 11.07.2017; Ogledov: 79; Prenosov: 3
Celotno besedilo (493,38 KB)
Biogas as a renewable energy sourceMatjaž Ošlaj
, Bogomir Muršec
, 2010, pregledni znanstveni članek
Opis: Renewable energy technology does not simply produce energy, heat and transport fuel, but also offers the opportunity to live in the footsteps of a reasonable future development. In Europe and other industrialized regions, the main reason for the development of renewable energy is the environment, in particular the concern in relation to global climate change and the need to improve security and diversity of energy supply. In the developing countries, they promise a new hope for renewable primary energy supply in regions without conventional energy and provide an opportunity for sustainable development. Productionof "green energy" from biogas, which is among the renewable energy sources, promises an environmentally less damaging way of obtaining energy by reducing CO emissions into the environment and reduces energy dependence on imported energy sources. Biogas production is of major importance for the sustainable use of agrarian biomass as renewable energy source.
Ključne besede: anaerobic digestion, biogas, manure, renewable energy
Objavljeno: 11.07.2017; Ogledov: 62; Prenosov: 6
Celotno besedilo (194,11 KB)
Partitioning the vertex set of ▫$G$▫ to make ▫$G \Box H$▫ an efficient open domination graphTadeja Kraner Šumenjak
, Iztok Peterin
, Douglas F. Rall
, Aleksandra Tepeh
, 2016, izvirni znanstveni članek
Opis: A graph is an efficient open domination graph if there exists a subset of vertices whose open neighborhoods partition its vertex set. We characterize those graphs ▫$G$▫ for which the Cartesian product ▫$G \Box H$▫ is an efficient open domination graph when ▫$H$▫ is a complete graph of order at least 3 or a complete bipartite graph. The characterization is based on the existence of a certain type of weak partition of ▫$V(G)$▫. For the class of trees when ▫$H$▫ is complete of order at least 3, the characterization is constructive. In addition, a special type of efficient open domination graph is characterized among Cartesian products ▫$G \Box H$▫ when ▫$H$▫ is a 5-cycle or a 4-cycle.
Ključne besede: efficient open domination, Cartesian product, vertex labeling, total domination
Objavljeno: 10.07.2017; Ogledov: 42; Prenosov: 4
Celotno besedilo (166,60 KB)
Utjecaj kvalitete voluminozne krme na proizvodnju kravljeg mlijeka u općini Ptuj
1995, izvirni znanstveni članek
Opis: Analizirana proizvodnja mlijeka na 10 seoskih gospodarstava općine Ptuj, gdje zaostaju prosječne količine proizvedenog mlijeka simentalske pasmine krava muzara za ostalim regijama Slovenije. Istraživana je kvaliteta, pripremljene količine voluminozne krme i njihov utjecaj na proizvodnju mlijeka. Ustanovljeno je, da u krmnim obrocima nisu izbalansirani: suha tvar, energija i bjelančevine. Obrocima nedostaju smjese mineralnih tvari i vitamina te stočna sol. Nedovoljna, proizvodnja dovoljnih količina osnovne voluminozne i koncentrirane krme na gospodarstvima onemogućuje maksimalno iskorištavanje proizvodnog potencijala krava muzara, koje su u razdoblju od 1987. do 1992. proizvele 3318 kg mlijeka s 3,74% mliječne masti u standardnoj laktaciji. Prosjek mliječnih bjelančevina praćen u razdoblju od 1990. do 1992. iznosio je 3,17%.
Ključne besede: voluminozna krma, laktacija, krmni obroki, proizvodnja mleka
Objavljeno: 10.07.2017; Ogledov: 60; Prenosov: 2
Celotno besedilo (2,36 MB)
The milk quality and feasibility analysis of loose housing dairy cowsMarjan Janžekovič
, Črtomir Rozman
, 2006, izvirni znanstveni članek
Opis: The aim of the study was technological and economical analysis of free range cow breeding. The case study analyzed two different systems of holstein-fresian dairy cows breeding. The model total costs enterprise budget was developed for evaluation of economic feasibility of loose housing dairy cows in comparison with tied cow breeding system. Computer supported calculation enabled estimation of the most important economical parameters (net return, observed input parameters) loose housing system is economically feasible, if there is a minimum of 41 dairy cows with an average milk production of 8610 kg per cow. It was also established that cows need approximately 6 months to fully adapt to the loose hausing system.
Ključne besede: loose housing, dairy cows, milk quality, coefficient of economy
Objavljeno: 10.07.2017; Ogledov: 58; Prenosov: 3
Celotno besedilo (221,55 KB)
The Influence of various origins of first calving Simmental and Black-White cows on production and content of milkMarjan Janžekovič
, Dejan Škorjanc
, Jože Smolinger
, 2004, izvirni znanstveni članek
Opis: A total of 1 070 Simmental and Black-White first calving cows and the same number of mother cows were investigated. The first calving cows originally arrived from Slovenia, the Netherlands, Germany and Denmark. No statistically significant differences were established in the milk production and quality of milk between the first calving cows from abroad compared to the first calving Slovenian cows. Statistically significant higher milk production (8 004 ± 981 kg; P ≤0.001) had mother cows of the imported Black-White compared to the Slovene (6 514 ± 1 142 kg) ones. There were no statistically significant differences, in the milk production and quality of milk, between the imported mothers of first calving cows of Simmental breed comparing with Slovenian mothers of first calving cows of the same breed. The milk production between the mothers and their Simmental daughters had a statistically significant correlation (rp = 0.125; P ≤ 0.01). The higher correlation coefficient for this characteristic was established between the Black-White mothers and their daughters (rp = 0.302; P ≤ 0.001). Among the milk production of first calving cows and protein content in milk a statistically negative significant correlation (rp = -0.198; P ≤ 0.001) was established. This result confirmed that the purchase of more expensive animals with better genetic potential is economically unjustified for the breeder who does not reach intensive technology of basic quality voluminous fodder.
Ključne besede: cattle, Simmental, Black-White, milk production, protein, fat
Objavljeno: 10.07.2017; Ogledov: 44; Prenosov: 2
Celotno besedilo (225,07 KB)