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The results obtained in the study showed that sheep subjected to a new stress factor (restraint) following twice-applied action of another stress factor (isolation from the flock), maximum ACTH concentration was considerably higher than in the group of sheep subjected to single restraint stress, whereas the values of maximum cortisol concentration were similar. It distinctly indicated a divergence in pituitary and adrenal gland activity during severe stress after another twice repeated stressor. The fact that cortisol concentration in blood plasma remained at a constant level during different combinations of stress factors and repetition of frequencies testifies to the autonomy of adrenal glands and their own ability to regulate cortisol release. In this case the plasma level of ACTH appears to be better than the cortisol marker of stress intensity in sheep within a wide range of stressor intensities and cortisol level is not an objective factor because its level in blood plasma does not change simultaneously. The reason for cortisol suppression release in this case is the necessity for the organism to keep a suitable rate of metabolism and control its excess during stress.
The aim of the experiment was to determine the RYR1 genotype and to analyse the distribution of osteochondrosis (OC) in wild boars from different regions of Lithuania. Hair and bone samples were collected from wild boars of various sexes and ages that had been shot during hunting season. Genomic DNA was extracted from hair roots. The RYR1 gene was analysed with the PCR-RFLP method, using specific primers and restriction enzymes Alw211 and Hin61. Only one C allele (q = 1.00) and CC genotype of the RYR1 gene were identified. Thus 138 genotyped wild boars were stress-resistant with both dominant alleles intact (no mutation). OC was measured by the cut surface of the distal femur and humerus. The prevalence of OC among the 34 wild boars tested was 20.6%. 5 animals (14.7%) had OC lesions in the hind legs and 2 animals (5.9%) had them in the front legs. OC affected leg joints more often in adult females (third-years and older), but this dependence was not significant (p > 0.05).
The results of studies conducted in 2006 revealed that mass red mite (Dermanyssus gallinae) invasions cause somatic stress which may be responsible for the pathophysiological mechanism of decreased egg production, lower humoral immunity and higher mortality in layer hens. The aim of this study was to validate the above research results, to investigate whether in addition to somatic stress, red mite invasions cause psychogenic stress due to the activation of the sympatho-ad- renomedullar system, and to determine the level of stress resulting from red mite infestations in comparison with a short, 1.5 h period of acute immobilisation stress. The study investigated 36 HY-Line Brown layer hens divided into three groups: a non-infested control group, an experimental group infested with red mites and a non-infested experimental group subjected to acute immobilisation stress for 1.5 h. Blood samples were taken from all hens for the determination of the levels of corticosterone, adrenaline, noradrenaline, albumin, and α-, ß- and y-globulins. The results validated the previous reports on the occurrence of somatic stress and on a significant decrease in y-globulin levels (p < 0.01) in the group of birds infested with red mites, in comparison with the control group. Adrenaline levels in infested hens were indicative of psychogenic stress. Based on a comparison of hormonal indicators in all hen groups, the level of somatic stress resulting from red mite infestation can be classified as moderate, while the level of psychogenic stress can be interpreted as high. A significant drop in y-globulin levels in the blood of birds infested with red mites also shows that the invasion induces chronic stress which lowers the humoral immunity of hens.
Preliminary study of memory processes in Mongolian gerbil (Meriones unguiculatus). Mongolian gerbil (Meriones unguiculatus) a small rodent living in the wild steppes of Mongolia was discovered in 1866 and it is becoming increasingly popular as a pet. The present work is an introduction to describe the behavior of this species and to investigate the influence of gender and age on memory process. 40 gerbils divided into four study groups (young males, young females, adult males, adult females) were twice tested in a modified version of the Lashley III maze (repeat after a week). Using statistical tests memory parameters, the activity of animals and behavior associated with the level of stress were analyzed. Conducted observations and calculations performed showed no difference between the groups (p > 0.05), which leads to the conclusion that in Mongolian gerbils age and sex have no effect on memory.
Blood parameter changes have been investigated after short-term road transport stress in 18 crossbred dairy cows in northwest of Iran. Cows were transported in 4 groups of four cows and one group of two cows in five different days. Each group was transported by truck up to a 40 km round trip for an hour. Blood was taken in 5 ml amounts from the jugular vein from each cow before transport and then repeated bleeding at 1.5 hours intervals up to 7.5 hours after transportation. Blood samples were assessed for cortisol, (ELISA), glucose, calcium (Ca), phosphorus (IP), magnesium (Mg) (spectrophotometer method), sodium (Na), potassium (K) (flame Photometer), total protein (TPP), fibrinogen (Refractometer method), leucocytes and differential count. Blood cortisol, glucose and leucocytes count increased up to 340%, 48.6% and 23% within 1.5, 7.5 and 6 hours after transport, respectively. Haematocrit decreased up to 17% after 7.5 hours transport. The mean differences (Wilk.s Lambda) for these parameters before and after transport were significant (P < 0.05). The mean differences for Ca, IP, Mg and eosinophil count were also significant (P < 0.05). The highest changes were observed for glucose, hematocrit after 7.5 hours, Ca and the leucocytes count after 6 hours, cortisol after 1.5 hours and the lymphocyte count after 3 hours of transportation. There were significant (P < 0.05) relationships between cortisol&Mg (r = .0.54), cortisol&TPP (r = .0.55), cortisol&fibrinogen (r = .0.52), cortisol&neutrophil (r = .0.52) cortisol & lymphocyte count (r = 0.79) 3 hours after transport. It is concluded that short-term road transport stress increased blood cortisol, that changes in the blood parameters are mainly due to glucose, hematocrit, and leucocyte count and blood electrolytes. Although these changes were within the reference range for cattle, since these parameters are known as health parameters in a ruminant.s life they should be considered during the transportation.
The aim of the study was to assess the level of stress hormones (cortisol and testosterone) in the blood of minks with a known behavioral profile based on the empathic test. The research was conducted on 100 one-year-old American mink (Neovison vison) females. The empathic test was performed according to the method described by Malmkvist and Hansen (2002) in triplicate with a two-week pause between tests. The test consisted of inserting a wooden stick into the living space of the animal. Animals were classified into four behavioral profiles: aggressive, curious, fearful and neutral. In the evaluation of stress level, the levels of testosterone and cortisol in postmortem blood were determined. Blood levels of testosterone (ng/ml) and cortisol (ng/ml) were determined by the ELFA method (Enzyme Linkes Fluorescent Assay). It has been shown that the behavioral profile of mink had no significant effect on the levels of testosterone and cortisol in the mink blood. Cortisol levels were similar in animals from all four behavioral profiles (40.6 to 46.0 ng / ml). The lowest level of testosterone was found in animals evaluated in the empathic test as aggressive and fearful (0.056 ng/ml and 0.071 ng/ml, respectively). Post mortem sampling reduces the effect of stress resulting from the blood collection itself, but the results of the study indicate that the determination of stress hormone levels in postmortem blood was a non-differentiating characteristic in the context of their behavioral profile.
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