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: 679; Prenosov: 74
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Possible role of jasmonic acid in the regulation of floral induction, evocation and floral differentiation in Lemna minor L.Božidar Krajnčič
, Janja Kristl
, Ignac Janžekovič
, 2006, izvirni znanstveni članek
Opis: Jasmonic acid (JA) is implicated in a wide variety of developmental and physiological processes in plants. Here, we studied the effects of JA and the combination of JA and ethylenediamine-dio-hydroxypheny-acetic acid (EDDHA) on flowering in Lemna minor in axenical cultures. JA (0.475-47.5 nmol l-1) enhanced floral induction in L. minor under long-day (LD) conditions. Under the same conditions, at the concentration of 237.5 nmol l-1, JA inhibited floral induction, and at the concentration of 475 nmol l-1 it prevented floral induction. Under LD conditions with LD preculture, a combination of EDDHA (20,500 nmol l-1) and JA (47.5 nmol l-1) had a synergistic effect on the promotion of floral induction. Floral induction was enhanced to the greatest extent in experiments with LD precultures. Microscopic examination of microphotographs of histological sections showed that JA and, to an even greater extent, JA+ EDDHA at optimal concentrations promote apical floral induction (evocation). Furthermore, and to an even greater extent JA in combination with EDDHA in an optimal concentration, also promote flower differentiation, especially the development of stamens, as is evident from themicrophotographs. The experimental results show that JA promotes floral induction in other species of Lemnaceae from various groups according to their photoperiodic response. The results support our hypothesis that, in addition to previosly ascribed functions, JA may regulate floral induction, evocation and floral differentiation. Our hypothesis is supported also by the results obtained by quantitative determination of endogenous JA levels in L. minor at three growth stages. The levels of endogenous JA decreased from 389 ng JA g-1 (fresh weight) of L. minor during the vegetative stage to 217 ng JA g-1 during the evocation stage, and to 37.5 ng JA g-1 during the flowering stage, which proves that JA is used for flowering.
Ključne besede: chelating agent EDDHA, flowering, jasmonic acid (JA), Lemna minor L., endogenous JA levels
Objavljeno: 10.07.2015; Ogledov: 911; Prenosov: 88
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PRELIMINARNA RAZISKAVA VPLIVA RAZLIČNIH KEMIČNIH SPOJIN NA RAST IN RAZVOJ ŠKRLATNEGA AMERIŠKEGA SLAMNIKAEchinacea purpurea (L.)Moench V KONTROLIRANIH RAZMERAHIvana Vukovski
, 2010, diplomsko delo
Opis: Raziskava je potekala v rastlinjaku Fakultete za kmetijstvo in biosistemske vede Univerze
v Mariboru na Pivoli pri Hocah (SV Slovenija). Glavni cilj naloge je bil priti do osnovnih
informacij o vplivu nekaterih kemijskih substanc (jasmonska kislina, salicilna kislina,
EDDHA in PHOSAMCO) v razlicnih koncentracijah na rast in razvoj škrlatnega
ameriškega slamnika (Echinacea purpurea (L.) Moench) v kontroliranih razmerah. Mlade
sadike smo namocili za 24 ur v odgovarjajoce koncentracije kemikalij in jih nato posadili v
lonce. Fenotipska analiza je vkljucevala 12 lastnosti, opravljena pa je bila, ko so rastline
dosegle stadij petih listov. Raziskava je pokazala, da so bile najbolj ucinkovite jasmonska
kislina (pri koncentraciji 0,03 mM) in salicilna kislina (pri koncentracijah 0,06; 0,6 in 1,2 mM.
Ključne besede: Kljucne besede: Echinacea purpurea, škrlatni ameriški slamnik, jasmonska kislina, salicilna kislina, EDDHA, rast rastlin, razvoj rastlin, fenotipske lastnosti.
Objavljeno: 30.03.2010; Ogledov: 2491; Prenosov: 200
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