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Objavljeno v RUNG: 29.03.2017; Ogledov: 4282; Prenosov: 81
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Opis: The experiment was aimed to evaluate the usefulness of hair cortisol concentrations (HCC) in revealing the activation of the hypothalamic-pituitary-adrenal (HPA) axis due to the passage of young bulls from genetic rearing stations to artificial insemination (AI) centre and the influence of this passage on hair testosterone concentrations (HTC). Hair samples on 33 yearling bulls were collected at the time of arrival (ST1) to the AI centre and 3 more hair samples (ST2, ST3, ST4) were collected at monthly intervals. After the end of quarantine each animal was submitted to the standard procedures for collection and production of semen. Overall HCC were significantly affected by period of collection (p<.01). In particular, HCC was higher in samples obtained after finishing the quarantine period (ST2) compared with those obtained on ST1. After ST2, the HCC decreased reaching at ST4 a value similar to that recorded at ST1. An effect of sampling time on HTC was not found (p>.05). The effect of breed was observed only for HTC that was higher in PRI than BS (p<.01). The HCC group have not influenced the semen variables (p>.05). On the contrary, the effect of breed was evident. The results of this study replicated the effects of a major environmental stressor on mean cortisol concentrations assessed in hair, and add to the growing body of evidence that HCC is an effective and simply collected marker for long-term activity of the HPA system in response to persistent environmental challenge.
Ključne besede: Hair, bulls, cortisol, testosterone, semen
Objavljeno v RUNG: 20.03.2017; Ogledov: 5613; Prenosov: 0
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Opis: Cortisol (C) is a major stimulus for fetal and neonatal lung maturation and for surfactant production. Neonatal calves born by caesarean section (CS), particularly the double-muscled Belgian Blue (BB), are more proned to develop the respiratory distress syndrome (Cambier et al. 2002 Vet Res 33, 283–290; Danlois et al. 2003 Vet J 165, 65–72). The aim of this study was to investigate C plasma levels in 15 Holstein Friesian (HF) newborn calves born by spontaneous vaginal delivery (VD) and in 25 BB newborn calves born by elective CS. Blood samples were taken at 10, 20, 30 min and at 6, 24 h after birth and at 7 and 14 days of age. Plasma C concentrations were analyzed by RIA. Statistical analysis evidenced an influence of both time (p < 0.05) and group (p < 0.0001) on C concentrations. In agreement with previous studies, high C levels at birth were followed by a reduction at 6 h and by a further decrease on day 7 after birth in both groups. Cortisol concentrations were different between BB and HF calves, with significantly higher levels in HF calves. These findings are in agreement with studies in newborn babies, while previous studies on calves mentioned no differences in C levels between calves born without assistance vs. calves born by CS. The present results suggest that both breed and type of delivery are associated with plasma C levels in the newborn calf.
Ključne besede: Plasma cortisol, Holstein Friesian, Belgian Blue, calf, delivery
Objavljeno v RUNG: 15.11.2016; Ogledov: 4533; Prenosov: 0
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Opis: We tested a method to measure Hair Cortisol Concentration (HCC) in 174 red deer (Cervus elaphus) culled in the hunting season 2011/12 in four areas of Central Italian Alps, with different population densities (SPN, 11.8 deer/km2; HD-AV, 3.6 deer/km2; HD-SO, 2.1 deer/km2; HD-MO, 2.0 deer/km2) and environmental conditions. Our hypothesis was that higher population densities, associated with more difficult environmental conditions, may result in higher allostatic load for these wild ungulates. No significant differences in HCC were detected between sexes (males, 4.77 ± 0.69 pg/mg; females, 5.75 ± 0.63 pg/mg) nor among age classes (calves, 6.17 ± 0.66 pg/mg; yearlings, 4.47 ± 0.83 pg/mg; adults, 5.15 ± 0.74 pg/mg; least square mean ± SE), but HCC difference between calves and yearlings was close to statistical significance (P = 0.059). HCC showed high individual variation, but on average it was higher in areas with higher deer density (SNP, 7.45 ± 1.01 pg/mg; HD-AV, 6.07 ± 0.89 pg/mg; HD-SO, 4.67 ± 1.14 pg/mg; HD-MO, 2.87 ± 1.56 pg/mg), with significant differences between HD-AV and HD-MO (P = 0.01). Carcass weight was significantly lower in SNP (46.74 ± 1.49 kg) than in HD-MO (62.71 ± 4.01 kg), HD-SO (61.73 ± 2.9 kg) and HD-AV (62.07 ± 2.04 kg) (P < 0.001). These results seem to confirm our hypothesis that allostatic load is higher in areas with higher density and harder environmental conditions. We suggest that the methodology used in this study to measure HCC provides good information on long-term HPA axis activity and allostatic load and constitutes a highly promising, reliable and non-invasive method in wildlife management for assessing HPA axis activity over extended time periods.
Ključne besede: Red deer, Cervus elaphus, Hair, Cortisol, Allostatic load
Objavljeno v RUNG: 29.09.2016; Ogledov: 4389; Prenosov: 0
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Opis: The karst ecosystem shows heterogeneity and variability of geology, hydrology, morphology and ecology in space and time. Chemical composition of water in karst plays a crucial role not only in dissolution of karst rocks and deposition but also in ecological processes. The heterogeneous nature of karst aquifers leads to difficulties in predicting groundwater flow and contaminant transport direction and travel times. For its position at the top of karst, epikarst represents the interface between surface and underground. Epikarst ecology, biodiversity and fauna have rarely been systematically studied. The typical absence of enterable passages makes necessary an indirect approach. In this research, epikarst biodiversity in relation to environmental conditions was studied in seven Alpine and Pre-Alpine caves, located at different altitudes, in Slovenia and in Italy: Snežna jama na planini Arto (1556 m a.s.l.), Jama pod Babjim zobom (860 m a.s.l.), Zadlaška jama (300 m a.s.l.) and Pološka jama (500 m a.s.l.), in Slovenian Alps and Pre-alps, and Grotta A del Ponte di Veja (600 m a.s.l.), Covolo della Croce (875 m a.s.l.) and Grotta di Roverè Mille (1005 m a.s.l.) in Lessinian Massif. In these caves, percolating water was monthly monitored for fauna in the period of one year. Temperature, discharge, conductivity and pH were measured at the same time, and water samples for the laboratory analyses of total hardness, concentrations of various ions (calcium, chlorine, nitrate, sulphate and phosphate) and dissolved organic carbon were taken. 66 aquatic and terrestrial, mostly hypogean, species were found. Aquatic fauna was dominant in all caves, with the exception of Covolo della Croce. Caves located at higher elevations harbour less diverse communities. No animals were found when discharge was very low and in correspondence of moonmilk formations. The most abundant and diverse group was Copepoda, with thirteen different species and 776 individuals at different maturity stadia, totally representing 61% of the community (between two and three copepod species per cave in Slovenia and between one and six per cave in Italy). The 62% of copepod species were stygobionts. Some copepod species (e.g. Speocyclops infernus) have wide ecological tolerance to environmental variables, other have more restricted tolerances (e.g. Lessinocamptus insoletus). With regard of copepods, there was a good agreement between the number of observed species and the total number of predicted species, confirming that the sampling method was appropriate and sampling complete. Correlations between the copepod community structure and measured parameters, obtained with Pearson correlation coefficient and principal component analysis (PCA) show different patterns. Presence of copepods was positively correlated with conductivity and dissolved organic carbon in Grotta di Roverè Mille, and with carbonate and nitrate in Pološka jama. In other caves not so high correlations were found between copepod species and measured parameters and between pairs of species. Investigations of the Alpine and Pre-alpine epikarst fauna can help to understand better the ecology of the epikarst fauna and its roles within the large range of different shallow subterranean habitats.
Ključne besede: Epikarst, Alpine and Pre-Alpine caves, percolating water, speleobiology, fauna.
Objavljeno v RUNG: 31.08.2016; Ogledov: 5386; Prenosov: 284
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