Central and peripheral effects of repeated noise stress on hypothalamic-pituitary-adrenocortical axis in pigs

The present study was performed to examine the effects of a repeated noise exposure (4 weeks) on basal and noise-induced plasma adrenocorticotrophin (ACTH), cortisol and corticosteroid binding globulin (CBG) levels, brain glucocorticoid receptors (GR) and corticotropin-releasing hormone (CRH) concentrations as well as on the morphology of adrenal glands in German Landrace pigs. Chronically cannulated pigs were exposed to either a daily stimulation with broad-band noise (2 h, 90 dB) (N1), or to the same stimulus three times a week (N2), or to an equal handling procedure without noise stimulation. Noise exposure caused an increase of basal CBG concentrations in N1 animals in the first week. During noise session, an increase of plasma ACTH and cortisol levels in N1 animals was measured in week 1 followed by a subsequent decrease until week 4. The ACTH and cortisol response of the N2 animals increased after week 1 and was significantly elevated in week 4. Furthermore, noise stress caused an increased hippocampal GR binding of N2 pigs, but had no effects on GR binding in the amygdala and on hypothalamic CRH levels. There were also significant structural modifications in the adrenal gland of N1 pigs resulting in differentiated effects on the adrenal cortex and medulla. The present results show that repeated noise exposure of pigs causes considerable alterations at different levels of the HPA system in association with the frequency of noise stimulation. This may have substantial impact on the general vulnerability of the animal with respect to productivity, health and welfare.     

STUDIES ON ALLERGIC DERMATITIS ("QUEENSLAND ITCH") OF THE HORSE

Studies have been made on a skin disease of horses in Australia, commonly known as "Queensland Itch" and referred to by the author as allergic dermatitis. It appears to be similar to conditions described by other workers in horses and mules in France, India, Philippine Islands and the United States of America.
The disease is prevalent during the summer and recedes with the advent of cold weather to recur the following summer. Only certain horses are susceptible but animals of all ages, breeds, colour and sex may be affected. Ani- mals show great irritation and itchiness and will bite affected areas or rub against fences and trees.
Lesions are confined almost exclusively to the dorsal surfaces and appear initially as discrete papules which later exhibit matting of the hair. These crusts eventually fall off and leave hairless areas which, in severe cases, become confluent.
Microscopic examination of early lesions shows oedema, engorgement of capillaries and eosinophilic infiltration of the dermis. In older lesions the oedema is absent and lymphoid cells are present with the eosinophils. Hyperkeratosis is seen in the more advanced cases and in chronic cases fibrosis and hypertrophy of epidermal tissue are well in evidence. In many animals trauma masks the earlier tissue changes.
Haematological examinations of susceptible animals revealed very little departure from normal. The white blood cells, eosinophils and platelets were, however, significantly higher in susceptible animals during the summer months.     

Morphological and genetic variability of local Echinochloa accessions and the link with herbicide sensitivity

Echinochloa crus‐galli and Echinochloa muricata are common weeds in Belgian maize fields. Both species are morphologically difficult to distinguish and exhibit high morphological variability. Their response to herbicides varies from field to field. This study investigated whether the considerable morphological polymorphism found among Belgian Echinochloa accessions has a genetic background and whether it is consistently associated with differences in sensitivity to maize herbicides. For this purpose, accessions of E. crus‐galli and E. muricata were compared for morphological and genetic resemblance and tested for herbicide sensitivity. All accessions were planted in the field to examine the morphological traits. A cluster analysis was conducted to assess them for morphological diversity. DNA of leaf material was used for amplified fragment length polymorphism analysis to cluster the accessions genetically. Dose–response pot experiments were conducted in the glasshouse to assess the effectiveness of an acetolactate synthase (nicosulfuron), acetyl‐CoA carboxylase (cycloxydim) and 4‐hydroxyphenyl phosphate dioxygenase (topramezone) inhibiting herbicide. The genetic and morphological clusters were compared with the effective doses obtained from the dose–response bioassays. Morphological variation significantly correlated with genetic variation, but the relation with herbicide sensitivity was weak. Spikelet size and biomass characteristics are reliable discriminating characteristics for (sub)species classification. Intraspecies identification does not seem essential for optimisation of chemical control of E. crus‐galli and E. muricata in the field.     

Genetic relationships among Hibiscus syriacus, Hibiscus sinosyriacus and Hibiscus paramutabilis revealed by AFLP, morphology and ploidy analysis

The genetic relationships between and within Hibiscus syriacus, Hibiscus sinosyriacus and Hibiscus paramutabilis, three winter hardy Hibiscus species native to China, were analysed by the amplified fragment length polymorphisms (AFLP) technique and by morphological evaluation of flower and leaf characteristics. Both methods clearly discriminated between the three species. H. sinosyriacus was classified as an intermediate form between H. paramutabilis and H. syriacus; however, it showed a higher similarity to H. paramutabilis. The different H. syriacus cultivars could be identified by AFLP analysis, while also leaf indices clustered the different cultivars in small groups. Flow cytometry showed that both triploid and tetraploid cultivars occur in the H. syriacus assortment. In general triploid cultivars had larger flowers compared to diploid cultivars.     

Unterschiedliche Formen der Resistenz gegen bodenbürtige Viren des Weizens

In Germany the furovirus Soil-borne cereal mosaic virus (SBCMV) and the bymovirus Wheat spindle streak mosaic virus (WSSMV) occur often together particularly in several rye production areas. Soil-borne wheat mosaic virus (SBWMV), a wheat infecting furovirus, has so far been found only in one field near Heidelberg. Each of these viruses is transmitted by Polymyxa graminis. The cultivation of resistant varieties is the only promising measure to prevent yield losses caused by soil-borne viruses. Resistance of wheat against the bymovirus WSSMV is comparable to the immunity of barley to the bymoviruses Barley yellow mosaic virus and Barley mild mosaic virus. In case of immunity no virus multiplication is observed in resistant cultivars. In contrast, all wheat cultivars are hosts of the furoviruses. All cultivars – including the resistant ones – can be infected following mechanical inoculation with SBWMV and SBCMV. Resistance to furoviruses is based on reduced levels of virus multiplication in roots and on inhibition of virus movement from roots to leaves. Because of the inhibited virus movement from roots to aerial parts of plants this type of resistance is referred to as translocation resistance. In spite of the different resistance mechanisms the absence of virus symptoms on the leaves is a common selection criterion for both immunity and translocation resistance. Therefore, the symptom free development of plants on uniformly infested fields is the best criterion for selecting wheat lines with resistance to soil-borne viruses. The limited suitability of other selection methods is discussed.     

A contribution to the classification of evergreen azalea cultivars located in the Lake Maggiore area (Italy) by means of AFLP markers

The amplified fragment length polymorphism (AFLP) technique was employed to assess the genetic conformity within a gene pool of evergreen azaleas. Ninety-three genotypes grown in historical gardens and nurseries of the Lake Maggiore area (Northern Italy), locally classified in the groups Indica, Japonica and Amoena, 44 reference cultivars of the four more or less universally recognized groups Belgian, Hirado, Kurume and Satsuki, and 40 species and species accessions that most concurred in the origin of the reference groups were included. Aims of the study were to define the genetic profiles of the Italian accessions and to provide useful information for their classification and pedigree reconstruction. Ordination analyses were used to evaluate if the AFLP technique can be applied to establish phylogenetic relationships and to investigate the DNA-based relatedness within the Italian gene pool and between the latter and the reference one. The results regarding the Italian accessions were compared with morphological data by means of Mantel’s test. Assignment tests both on the level of the groups and on individual plant level for the reference and Italian genotypes were applied to further evaluate the relatedness of the groups or individual accessions. Results demonstrated that the AFLP technique together with morphological characterization can contribute to depict the phylogeny of the evergreen azalea. Comparing the reference and Italian genotypes, conclusions about the classification of the evergreen azalea cultivars located in the Lake Maggiore area were drawn.     

Evaluation of carbon dioxide anaesthesia for the castration of male suckling piglets by stress hormone concentrations, behaviour and clinical factors

The objective of this study was to examine the effect of an anaesthesia using 70% carbon dioxide and 30% oxygen on endocrine stress reaction, behaviour and clinical parameters of male suckling piglets during castration. One hundred and seventy one male piglets, three to five days of age, were allocated to two experiments. They were assigned either to the procedures control handling, control castration, handling under anaesthesia or castration under anaesthesia in each experiment. In Experiment 1, adrenaline and noradrenaline plasma concentrations were measured in blood samples taken before (-15 min) and after (immediately, 2 min) handling/castration. In Experiment 2, behavioural observations and clinical parameters such as heart and respiratory rate, oxygen saturation, reflexes and recovery time were assessed at several sampling times. Measurement of adrenaline and noradrenaline concentrations revealed an increase in all groups after handling/castration (p < 0.0167), but higher concentrations were seen in the anaesthetized groups (25 to 93 times) than in control groups (two to four times). The excessive endocrine reaction suggests that carbon dioxide inhalation causes a more stressful situation in piglets compared to castration without anaesthesia. Behavioural abnormalities, significant decreases in the heart rate, the respiratory rate and the oxygen saturation (p < or = 0.001) including a cardiac arrhythmia (extrasystoles) underline the impression that CO2 inhalation anaesthesia negatively affects animal welfare. Based on the results of this study, this anaesthetic method is unsuitable to reduce stress induced by castration. Further research on alternatives is necessary to ensure the well-being of the piglets during castration.