Comparison of follicular and oocyte development and reproductive hormone secretion during the ovulatory period in Hungarian native breed, Mangalica, and Landrace gilts

Only a very small amount of physiological data is available about the low fertility (mean litter size is 5.7+/-0.8) of Hungarian native breed, Mangalica (M), sows. The aim of the present paper is to reveal the differences in preovulatory follicle development and intrafollicular oocyte maturation between M and Landrace (L) gilts, with special reference to the peri- and postovulatory secretion and peripheral concentrations of estradiol-17beta (E2), progesterone (P4), and luteinizing hormone (LH). The number of preovulatory follicles was 6.8+/-1.4 and 19.6+/-6.6 in M and L gilts, respectively. A lower degree of cumulus expansion and a lower percentage of mature oocytes (TI/M II) was noted in M. Higher LH and E2 peak levels, a longer E2 to LH peak interval, and lower embryo survival was confirmed. Interestingly, despite the lower number of corpora lutea, a higher peripheral blood level of P4 was shown in M than in L gilts. Both diminished follicular development and protracted oocyte maturation may be involved in low fecundity in M, and the present findings may explain these reproductive phenomena.     

Alteration of reproductive hormone levels in pregnant sows induced by repeated ACTH application and its possible influence on pre- and post-natal hormone secretion of piglets

Prenatal stress has been seen as a reason for reproductive failures in pig offspring mostly originated or mediated by changed maternal functions. Experiments were conducted in pregnant gilts (n=32) to characterize effects of elevated maternal glucocorticoids on the secretion of reproductive hormones (LH, progesterone) during the 1st (EXP 1), 2nd (EXP 2) and 3rd (EXP 3) trimester of pregnancy (TP). Transiently elevated cortisol release was repeatedly achieved by application of 100 IU adenocorticotropic hormone (ACTH) (Synacthen Depot) six times every second day beginning either on day 28 (EXP 1), day 49 (EXP 2) or day 75 of pregnancy (EXP 3). Glucocorticoid concentrations were examined in umbilical blood vessels of fetuses which mothers were subjected to ACTH at 2nd and 3rd TP (EXP 4). Furthermore, the pituitary function of newborn piglets of EXP 2 was checked by a LH-RH challenge test. In sows, LH concentrations were at low basal level (0.1-0.2 ng/ml) but with pulsatory release pattern during each TP. The number of LH pulses/6 h (LSM +/- SE) of saline treated Controls increased with ongoing pregnancy and decreased to the 3rd TP (1.3 +/- 0.2 in EXP 1 vs. 2.0 +/- 0.1 in EXP 2 vs. 1.4 +/- 0.1 in EXP 3, p<0.05). After ACTH treatment the number of LH pulses left unchanged in Experiments 1 and 2 (1.3 +/- 0.2 and 1.5 +/- 0.1) and decreased in EXP 3 (0.8 +/- 0.2, p<0.05). Differences (p<0.05) were obtained comparing the LH pulse number of ACTH and saline treated sows at the 2nd and 3rd TP. Moreover, areas under the curve (AUC) of each LH pulse and of LH over baseline were significantly reduced by treatment. Levels of progesterone increased (p<0.05) for 150 to 170 min after each ACTH application both in EXP 1 and EXP 2, but not in EXP 3. The mean progesterone concentration was different between trimesters, and ACTH and Controls (1st TP: 30.0 +/- 0.9 and 24.4 +/- 0.7 ng/ml; 2nd TP: 35.5 +/- 0.9 and 29.1 +/- 1.0 ng/ml; 3rd TP: 13.6 +/- 0.2 and 13.1 +/- 0.1 ng/ml; p<0.05). In fetuses (n=87) recovered 3 h after ACTH or saline (EXP 4), the plasma cortisol concentrations were significantly increased in umbilical vein (93.7 +/- 5.5 vs. 47.0 +/- 5.3 nmol/l) and artery (95.7 +/- 5.4 vs. 66.4 +/- 5.4 nmol/l), and in periphery (46.8 +/- 5.3 vs. 27.1 +/- 5.3 nmol/l) compared to controls. Plasma ACTH concentrations, however, did not differ in fetuses of both treatment groups. Postnatal LH-RH challenge tests (1st and 28th day post partum) induced LH surges in female piglets (n=67) both of ACTH and saline treated sows, but did not differ between groups (1st day: 7.2 +/- 0.8 vs. 8.1 +/- 0.7 ng/ml; 28th day: 10.5 +/- 1.7 vs. 13.6 +/- 2.2 ng/ml). However, basal LH of piglets whose mothers were submitted to ACTH during 2nd TP was lower on 1st day (1.7 +/- 0.2 vs. 2.3 +/- 0.2 ng/ml, p<0.05) but not on 28th day (1.0 +/- 0.2 vs. 1.1 +/- 0.2 ng/ml). However in both groups, the basal LH was always higher on 1st as on 28th day (p<0.05). Thus, chronic intermittent ACTH administration is able to influence the release pattern of maternal reproductive hormones. However, these findings demonstrate that these effects are dependent on the stage of pregnancy. Furthermore, it was shown that maternal cortisol can cross the placenta during gestation and thus may affect maternal-fetal interactions and, as a result, reproductive function of offspring.     

Histoplasmosis in dogs and cats

Histoplasma capsulatum is endemic throughout most of the United States with a high prevalence of infections in the Midwest and South. Histoplasmosis is the second most common systemic fungal disease in cats that may be more susceptible than dogs. Infection occurs by inhalation of conidia from the mycelial phase, which subsequently convert to the yeast form. Histoplasma capsulatum is phagocytized and harbored by cells of the mononuclear phagocyte system. Infection may be subclinical or cause clinical pulmonary granulomatous disease or dissemination. Disseminated disease predominantly affects the liver, spleen, gastrointestinal tract, bone and bone marrow, integument, and eyes. Primary gastrointestinal histoplasmosis also occurs. Clinical signs of histoplasmosis often are nonspecific, including chronic wasting, fever, anorexia, respiratory signs, and lameness. Gastrointestinal signs (eg, diarrhea with hematochezia or melena) are common in dogs. The definitive diagnosis is made by identification of the yeast in tissue samples. Itraconazole is the treatment of choice.     

Der Beitrag der Fernerkundung zur Erfassung der Waldschäden

European Journal of Forest Research - Im Zusammenhang mit der Erfassung und Verfolgung der Waldschäden kommt der Fernerkundung wachsende Bedeutung zu. Während für den Einsatz des...     

The humoral and cellular immune response of sheep against Borna disease virus in endemic and non-endemic areas

Borna Disease (BD) is a mostly fatal disease of horses and sheep endemic in central Europe. Antibodies to Borna disease virus (BDV) have been described in sheep and other species living in BD non-endemic areas. Meaningful clinical BDV serology is hampered by difficulties in defining serological cut-offs, which require the investigation of populations from endemic areas. Here we studied BD serology in sheep from endemic and non-endemic areas of similar geography in Switzerland. Antibodies to BDV antigens were detected by ELISA and indirect immunofluorescence analysis (IFA) only in sera from 3 of 6 sheep with autopsy confirmed BD. One serum was positive by IFA but not by ELISA, while 2 sera were negative in both assays, indicating that not all diseased animals develop BDV specific antibodies. Six % of clinically healthy animals (6/106) from an endemic area and 2% from a non-endemic area (4/192) had serum antibody to either BDV p40 or p24 as detected by ELISA. None of the animals showed a cellular immune response to BDV p40. In some healthy sheep from the endemic area, serum antibody titers to BDV p24 antigen remained elevated over several months without onset of disease symptoms. Infections with either BDV or related viruses may thus occur at low frequency in sheep from non-endemic areas leading to the production of antibodies to BDV antigens. We further propose viral strain differences or environmental factor(s) may determine the clinical outcome.     

Effects of diets with cereal grains contaminated by graded levels of two Fusarium toxins on selected immunological and histological measurements in the spleen of gilts

Feeding experiments with diets containing Fusarium toxin-contaminated wheat were conducted to clarify the pathogenesis of immunological effects of Fusarium toxins to porcine spleen cells. Contaminated diets were fed to 36 Landrace prepubertal gilts for 35 d. Concentrations (as-fed basis) of the indicator toxins deoxynivalenol (DON) and zearalenone (ZON), respectively, were 210 and 4 (control--group I), 3,070 and 88 (group II), 6,100 and 235 (group III), and 9,570 and 358 microg/kg (group IV). No signs of hyperestrogenism or uterotrophic effects were observed because of dietary treatments. The feeding of mycotoxin-contaminated diets did not cause gross pathological findings in the spleens of animals. In vivo, no inhibitory effects were detected on concanavalin A-stimulation of blood lymphocytes; however, the proliferation rate of splenocytes was inhibited (P < 0.05) in pigs fed the diet with the highest DON/ZON concentration. With in vitro studies, lower proliferation rates of blood lymphocytes and splenocytes preexposed to DON were detected. Serum IgA concentrations of pigs in group II were increased (P < 0.05) compared with the baseline value before feeding the DON/ZON diet. The histopathological data indicated elevated (P < 0.05) iron staining in the red pulp of spleens in gilts from groups I to IV after 35 d of feeding. The presence of hemosiderin particles in the spleen sections was confirmed by transmission electron microscopic investigation. Together, the results provide evidence of spleen dysfunction (hemosiderosis) in the absence of clinical signs, especially in pigs fed higher concentrations (groups III and IV) of Fusarium toxin-contaminated wheat.     

Pheno- and genotyping of Staphylococcus epidermidis isolated from bovine milk and human skin

The purpose of this study was to improve our knowledge concerning the epidemiology and strain diversity of Staphylococcus epidermidis isolated from bovine milk in commercial dairy herds. A total of 341 S. epidermidis isolates obtained from cows' milk (317), farmers (17) and patients (7) were characterized. Of these 105 isolates were from cows' milk in two farms, where also 17 isolates were sampled from farmers. The remaining 212 isolates from cows' milk were from 170 farms. All isolates were examined by antimicrobial susceptibility, whereas 202 were examined by pulsed-field gel electrophoresis (PFGE) and 122 by ribotyping. PFGE showed single patterns in the human strains with one exception; one strain was categorised as the same clone as four of the milk strains. PFGE divided 73 of the milk strains into 62 different patterns. The PFGE method had high discriminatory power and shows that many different S. epidermidis types exist in milk samples. Antibiotic resistance patterns matched the SmaI profiles closely in the two herds, but poorly in the routinely collected milk samples. Isolates from herd 1 showed one to five patterns, depending on the typing method used. Isolates from the milker's skin showed one pattern, which was identical to the most common pattern found in the milk isolates. Isolates from herd 2 showed three to four patterns, two of these being identical to skin isolates from the milker. As dairy cows are not a natural host for S. epidermidis the results suggest a human source of these udder infections.     

Discovery of a young planetary-mass binary

We have identified a companion to the young planetary-mass brown dwarf Oph 162225-240515. This pair forms a resolved binary consisting of two objects with masses comparable to those of extrasolar giant planets. Several lines of evidence confirm the coevality and youth of the two objects, suggesting that they form a physical binary. Models yield masses of approximately 14 and approximately 7 times the mass of Jupiter for the primary and the secondary object, respectively, at an age of approximately 1 million years. A wide ( approximately 240-astronomical unit) binary in the ultra-low-mass regime poses a challenge to some popular models of brown dwarf formation.     

The complex symbiotic relationships of bark beetles with microorganisms: a potential practical approach for biological control in forestry

Bark beetles, especially Dendroctonus species, are considered to be serious pests of the coniferous forests in North America. Bark beetle forest pests undergo population eruptions, causing region wide economic losses. In order to save forests, finding new and innovative environmentally friendly approaches in wood-boring insect pest management is more important than ever. Several biological control methods have been attempted over time to limit the damage and spreading of bark beetle epidemics. The use of entomopathogenic microorganisms against bark beetle populations is an attractive alternative tool for many biological control programmes in forestry. However, the effectiveness of these biological control agents is strongly affected by environmental factors, as well as by the susceptibility of the insect host. Bark beetle susceptibility to entomopathogens varies greatly between species. According to recent literature, bark beetles are engaged in symbiotic relationships with fungi and bacteria. These types of relationship are very complex and apparently involved in bark beetle defensive mechanisms against pathogens. The latest scientific discoveries in multipartite symbiosis have unravelled unexpected opportunities in bark beetle pest management, which are discussed in this article.