Artificial insemination in the anoestrous and the postpartum white rhinoceros using GnRH analogue to induce ovulation.

The objective of this study was to develop AI and to achieve first time pregnancy in a nulliparous rhinoceros. For this, one 24-year-old irregular cycling female white rhinoceros was selected, which had never been mated. The endocrine function was monitored by faecal and serum pregnane analysis. Ultrasound determined the optimal day for AI by measuring follicle sizes of 2.0, 2.6, 3.0, 3.2 cm on days -6, -4, -1, 0 of the induced oestrous cycle, respectively. AI was performed and ovulation induced when a pre-ovulatory-sized follicle was present using GnRH analogue, deslorelin. Fresh semen was deposited in the uterine horn using a patented AI catheter overcoming the hymeneal membrane and torturous cervical folds non-surgically. Moreover, ultrasound monitoring of the uterine involution and ovarian activity on days 16, 26, 30 postpartum facilitated the induction of and the AI on the first postpartum oestrous in a rhinoceros using GnRH analogue. Two consecutive pregnancies were achieved by AI for the first time in the rhinoceros. Pregnancies were diagnosed by elevated serum and faecal 20-oxo-pregnane concentrations. In addition ultrasound measured biometric parameters of the two foetuses on days 86 and 133 of gestation. Two female calves were born after 490 and 502 days of gestation, yet one calf was stillborn. AI in rhinoceros might now be used as assisted reproduction technology tool to boost critically small captive rhinoceros populations.

Histological organization of roe deer testis throughout the seasonal cycle: variable and constant components of tubular and interstitial compartment.

Seasonally regulated breeding in roe deer, Capreolus capreolus, is associated with significant changes in testis mass, structure and function. This study has quantified seasonal changes of morphometric parameters and cellular composition in roe deer testis parenchyma. Tissue samples were collected bimonthly during a complete annual cycle. Morphometric parameters of seminiferous tubules were measured and the number of different cell types was counted using a computer-aided image-analyzing system. A scheme of eight tubular epithelium stages for active spermatogenesis was devised according to the spermatid development. Stage I is characterized by the occurrence of new round spermatids, stage IV by spermiation and stage VIII by the meiotic division of spermatocytes. The average diameter of seminiferous tubules varied between 88.4+/-3.6 micro m (February) and 216.8+/-9.2 micro m (June). Also numbers of spermatogonia, spermatocytes and spermatids per tubule cross-section showed considerable seasonal changes. In December and February the germinative epithelium mainly consists of Sertoli cells and spermatogonia. In February, the first differentiated spermatogonia enter meiosis, and in April even spermatids occasionally occur, which reach their highest numbers during the rut in August. Both the expansion and the proportion of tubular and interstitial compartment change seasonally and result in differing cell densities. Assuming numerically constant populations of Sertoli cells and interstitial cells during the entire year, the hypothetical cell numbers per mm(2) of the tubular and interstitial areas were calculated for the seasonally variable total areas of tissue cross-sections. The concordance of these theoretical values with measured cell densities provided evidence that the total numbers of Sertoli cells, as well as interstitial cells, remain really constant throughout the seasonal cycle. The exact quantification of variable and constant components provides basic data for characterization of cell type and stage-specific processes of spermatogenesis.

Intralaboratory validation of alternative endpoints in the murine local lymph node assay for the identification of contact allergic potential: primary ear skin irritation and ear-draining lymph node hyperplasia induced by topical chemicals.

We validated a two-tiered murine local lymph node assay (LLNA) with a panel of standard contact (photo)allergens and (photo)irritants with the aim of improving the discrimination between contact (photo) allergenic potential and true skin (photo)irritation potential. We determined ear weights to correlate chemical-induced skin irritation with the ear-draining lymph node (LN) activation potential. During tier I LLNAs, a wide range of concentrations were applied on three consecutive days to the dorsum of both ears. Mice were exposed to UVA light immediately after topical application to determine the photoreactive potential of some test chemicals. Mice were killed 24 h after the last application to determine ear and LN weights and LN cell counts. It was possible to classify the tested chemicals into three groups according to their threshold concentrations for LN activation and skin irritation: (1) chemicals with a low LN activation potential and no or very low skin irritation potential; (2) chemicals with a marked LN activation potential higher than a distinct skin irritation potential; and (3) chemicals with LN activation potential equal to or lower than their skin irritation potential. Group 1 consisted only of contact allergens, indicating that LN activation in the absence of skin irritation points to a contact allergenic activity. Since groups 2 and 3 comprised irritants and contact allergens, a tier II LLNA protocol was used to finally differentiate between true irritants and contact allergens. Briefly, mice were pretreated with mildly to moderately irritating concentrations of the chemical to the shaved back and after 12 days were challenged on the ears as described above in order to elicit a contact allergenic response in the ear skin and the ear-draining LN. With this approach, tier II LLNAs have to be conducted only in cases for which skin irritation potential is in the range of LN activation potential and no structure-activity relationship data indicating a contact allergenic hazard are available.

Seroepizootiology of selected infectious disease agents in free-living birds of prey in Germany.

Four hundred forty-eight blood plasma samples from free-living birds of prey from Berlin and the Brandenburg area in eastern Germany were tested for antibodies against Newcastle disease virus (NDV), falcon herpesvirus (FHV), owl herpesvirus (OHV), and Chlamydia psittaci. Antibodies to NDV were detected in 6 (2%) of 346 tested diurnal birds of prey, whereas none of the owls (n = 55) was positive. The positive samples originated from two common buzzards (Buteo buteo), three ospreys (Pandion haliactus) and one marsh harrier (Circus aeruginosus). Titers varied between 1:8 and 1:32. Of 253 birds of prey one osprey (<1%) tested positive for antibodies to FHV with low titer of 1:6. This is the first detection of antibodies against FHV in an osprey. Furthermore, antibodies against OHV could be found in one tawny owl (Strix aluco) and one common buzzard (2 of 253, 1%) with low titers of 1:6. Of 422 birds of prey 267 (63%) tested positive for antibodies to Chlamydia psittaci with titers varying between 1:5 and 1:256 which reflects the ubiquitous occurrence of Chlamydia psittaci in these birds of prey.

Hemoglobin concentration in multiple versus singleton pregnancies--retrospective evidence for physiology not pathology.

OBJECTIVE: To describe hemoglobin (Hb) levels and percentiles for multiple pregnancies and to compare them with reference ranges of singleton pregnancies as published by the Center for Disease Control. STUDY DESIGN: Maternal hemoglobin and red cell indices were compared: (a) between multiple and singleton pregnancies of our hospital and (b) with trimester-specific cut-offs for singleton pregnancies obtained from literature. RESULTS: While early pregnancy hemoglobin values were similar in multiple and singleton pregnancies, second trimester values decreased much faster in multiple pregnancies. Nadir in multiple pregnancies was reached in weeks 24-28 of gestation. In the third trimester mean hemoglobin values were higher in multiple pregnancies, while 5th and 10th percentile were still lower compared to singleton pregnancies at term. The mean whole-pregnancy hemoglobin exceeded the Center for Disease Control (CDC) cut-off for anemia in singleton pregnancies (fifth percentile) and red cell indices remained constant. CONCLUSION: We conclude that with a significantly lower fifth percentile than introduced by the CDC in all trimesters, there should be different cut-offs for anemia in multiple pregnancies considered. A more pronounced decrease in multiple pregnancy hemoglobin levels seems to be physiological.

Influence of environmental cadmium on testicular proliferation in roe deer.

The influence of cadmium on spermatogenesis in roe deer was studied, comparing animals from areas with high (n = 37) and low (n = 23) cadmium exposure. Testes were evaluated during pre-rut (May) and rut (July/August). During these periods the cadmium accumulation (mg/kg kidney) in polluted regions averaged 3.41 and 3.52 in comparison with 1.61 and 1.81 in controls. Cadmium accumulation was positively correlated with testis weight during both seasons. In May the proliferation (units of tissue polypeptid specific antigen/g parenchyma) was lower in animals with higher cadmium (24.02 compared with 78.20; P < 0.01). During the rut, testicular proliferation and spermatozoa/g testis as well as apoptosis showed no significant changes with increased cadmium contamination. The results suggest delayed proliferation during the pre-rutting period in animals with high cadmium exposure, but other indications of effects on the testis were not significant.