Single-grain 40Ar-39Ar ages of glauconies: implications for the geologic time scale and global sea level variations

The mineral series glaucony supplies 40% of the absolute-age database for the geologic time scale of the last 250 million years. However, glauconies have long been suspected of giving young potassium-argon ages on bulk samples. Laser-probe argon-argon dating shows that glaucony populations comprise grains with a wide range of ages, suggesting a period of genesis several times longer ( approximately 5 million years) than previously thought. An estimate of the age of their enclosing sediments (and therefore of time scale boundaries) is given by the oldest nonrelict grains in the glaucony populations, whereas the formation times of the younger grains appear to be modulated by global sea level.     

Influence of milking technique and lactation on the bovine teat by means of ultrasonographic examination

The teats of Brown Swiss and Austrian Simmental cows, divided into two groups, one milked by means of an automatic milking system, the other using a conventional milking parlour, were examined monthly by ultrasonography. Aim of the study was to compare the effects of two different milking machines upon the structures of the bovine teat canal and wall by ultrasonography and thereby evaluate ultrasonography as a research tool for visualisation of different influences on the bovine teat. Length and thickness of the teat canal and teat wall thickness were measured and analysed. During lactation, teat canal length and thickness increased in both groups, teat canal length decreased in conventional milked cows at the end of lactation. Shorter and narrower teat canals were observed in automatic milked cows. Differences between the groups in teat canal length and thickness were determined in early lactation. During lactation teat wall thickness showed a slight increase. Automatic milked cows displayed thinner teat walls than cows milked in the milking parlour. Teat morphology was influenced by the number and duration of lactations, milk yield, quarter of the udder and time and date of examination. It was concluded that the effect of the two different milking machines caused significant differences in bovine teat morphology and that ultrasonography proved to be an appropriate method for visualising influences of the milking technique on the bovine teat.     

Effects of Hypo‐ and Hyperthyroidism on Proliferation,Angiogenesis, Apoptosis and Expression of COX‐2 in the Corpus Luteum of Female Rats

Although thyroid dysfunction occurs frequently in humans and some animal species, the mechanisms by which hypo‐ and hyperthyroidism affect the corpus luteum have not been thoroughly elucidated. This study evaluated the levels of proliferative activity, angiogenesis, apoptosis and expression of cyclooxygenase‐2 in the corpus luteum of female rats with thyroid dysfunction. These processes may be important in understanding the reproductive changes caused by thyroid dysfunction. A total of 18 adult female rats were divided into three groups (control, hypothyroid and hyperthyroid) with six animals per group. Three months after treatment to induce thyroid dysfunction, the rats were euthanized in the dioestrus phase. The ovaries were collected and immunohistochemically analysed for expression of the cell proliferation marker CDC‐47, vascular endothelial growth factor (VEGF), VEGF receptor Flk‐1 and cyclooxygenase‐2 (COX‐2). Apoptosis was evaluated using the TUNEL assay. Hypothyroidism reduced the intensity and area of COX‐2 expression in the corpus luteum (p < 0.05), while hyperthyroidism did not alter COX‐2 expression in the dioestrus phase. Hypothyroidism significantly reduced the expression of CDC‐47 in endothelial cells and pericytes in the corpus luteum, whereas hyperthyroidism did not induce a detectable change in CDC‐47 expression (p > 0.05). Hypothyroidism reduced the level of apoptosis in luteal cells (p < 0.05) and increased VEGF expression in the corpus luteum. In contrast, hyperthyroidism increased the level of apoptosis in the corpus luteum (p < 0.05). In conclusion, thyroid dysfunction differentially affects the levels of proliferative activity, angiogenesis and apoptosis and COX‐2 expression in the corpus luteum of female rats.     

Effect of TGF‐β1 Superfamily Members on Survival of Buffalo (Bubalus bubalis) Embryonic Stem‐like Cells

This study examined the effects of supplementation of ES‐like cell culture medium with bone morphogenetic protein (BMP)‐4 (0, 10, 20 or 100 ng/ml) or Noggin (250, 500 or 750 ng/ml) or TGF‐β1 (0, 0.1, 1 or 10 ng/ml) or SB431542 (0, 10, 25 or 50 μm ), an inhibitor of TGF‐β1 signalling, on survival, colony area and expression level of pluripotency genes in buffalo ES‐like cells at passage 40–80, under different culture conditions. BMP‐4 supplementation significantly reduced (p < 0.05) colony survival rate, percentage increase in colony area and relative mRNA abundance of OCT4, whereas that of NANOG and SOX‐2 was increased significantly (p < 0.05). Noggin supplementation did not affect the colony survival rate and percentage increase in colony area in the presence of FGF‐2 and LIF. In the presence of FGF‐2 alone, it significantly reduced (p < 0.05) the relative mRNA abundance of OCT4 and SOX‐2 and increased (p < 0.05) that of NANOG. Supplementation with TGF‐β1 at 1.0 ng/ml but not at other concentrations increased colony survival rate but had no effect on percentage increase in colony area at any concentration. Supplementation with SB‐431542 decreased (p < 0.05) colony survival rate at 50 μm but not at other concentrations. The percentage increase in colony area was lower (p < 0.05) with 10 μm SB‐431542 than that in the controls, whereas at higher concentrations of 25 or 50 μm , SB‐431542 decreased (p < 0.05) the colony size instead of increasing it. In conclusion, these results suggest that BMP‐4 induces differentiation in buffalo ES‐like cells, whereas TGF‐β/activin/nodal pathway may not be playing a crucial role in maintaining pluripotency in these cells.     

Lactation Weight Loss in Primiparous Sows: Consequences for Embryo Survival and Progesterone and Relations with Metabolic Profiles

Our objective was to study reproductive consequences of lactation bodyweight loss occurring in primiparous sows with mild feed restriction and to relate these lactation weight losses and its consequences to metabolic profiles during lactation and subsequent early gestation. After weaning, 47 first‐litter sows were retrospectively assigned to a high– (HWL, >13.8%, n = 24) or low (LWL, ≤13.8%, n = 23)–weight loss group. Thirty‐six animals received an indwelling jugular vein catheter to determine lactational and gestational profiles of insulin‐like growth factor‐1 (IGF‐1), non‐esterified fatty acids (NEFA) and urea and gestational profiles of progesterone. At day 35 after insemination, sows were euthanized and their reproductive tract collected. Pregnancy rate was 75% (18/24) for HWL and 96% (22/23) for LWL sows. High–weight loss sows had a lower number of implantation sites (17.2 ± 0.8 vs 19.5 ± 0.7, respectively, p = 0.03) and a lower embryonic survival (65.6 ± 3.4 vs 77.4 ± 2.9%, p = 0.02), resulting in fewer vital embryos (14.9 ± 0.9 vs 16.8 ± 0.7, p = 0.07) than LWL sows. Progesterone peak values were reached later in HWL than in LWL sows (day 13.4 ± 0.5 vs 12.0 ± 0.5, respectively, p = 0.05). Gestational concentrations of IGF‐1, NEFA and urea were almost identical for HWL and LWL sows, whilst numerical differences were seen during lactation. The current study shows negative consequences of lactational weight loss in mildly feed‐restricted primiparous sows for embryonic survival and shows that these consequences seem only mildly related with metabolic alterations during lactation and not with metabolic alterations during subsequent gestation.     

Effect of Repeated Stress Treatments During the Follicular Phase and Early Pregnancy on Reproductive Performance of Gilts

In pig husbandry, stress is being considered an important cause of impaired reproductive performance. Therefore, an experiment was performed to quantify effects of repeated stressors during the follicular phase and/or during early pregnancy on reproductive performance of gilts. Eighty-one cyclic gilts were assigned to one of four treatments, namely, stress treatment during the follicular phase (n = 20), stress treatment during early pregnancy (n = 20), stress treatment during both phases (n = 21) and no stress treatment (n = 20). All gilts were housed individually, but gilts in the stress treatments had no opportunity for visual or physical contact with other gilts. Further, animals in a stress-treatment were grouped for half an hour at the start of the treatment and during the treatment period nose-sling and an unpredictable feeding scheme were applied regularly. The extent of stress was monitored using heart rate measurements, behavioural observations and saliva cortisol levels during nose-sling fixation. Of the 81 gilts, 93% showed oestrus and were inseminated. Of these, 93% were pregnant at day 35, having 17.9 +/- 0.3 ovulations and 15.6 +/- 0.3 foetuses. These parameters were not affected by treatment. The stress treatment during the follicular phase tended to shorten cycle length (stress: 20.8 +/- 0.20; control: 21.2 +/- 0.17 days, p = 0.07) and weight of foetuses at day 35 (stress: 4.47 +/- 0.08 g; no stress: 4.69 +/- 0.08 g, p = 0.06); stress during early pregnancy did not affect any of the reproduction parameters. Percentage stereotypic behaviour, heart rate and saliva cortisol levels varied greatly between animals and between days, but did not differ between the treatments. No relationships were found between any of the reproductive parameters and any of the stress parameters (heart rate, cortisol, stereotypic behaviour). These results indicate that the repeatedly applied acute stressors did not generate a chronic stress-response and that these stressors during the follicular phase and/or during early pregnancy did not affect reproductive processes. It is not clear how these findings relate to suggested effects of stress(ors) on reproductive performance in pig husbandry.     

Pregnancy-associated Glycoprotein Profile during the First Trimester of Pregnancy in Egyptian Buffalo Cows

Pregnancy-associated glycoprotein (PAG) concentrations were measured in buffalo cows starting from day 28 after breeding. Oestrus was synchronized in 10 buffaloes using two injections of 25 mg prostraglandin (PG)F_{2 α} (Lutalyse^®) at a 11-day interval. Blood sampling was conducted nearly twice weekly. Results indicated that plasma PAG concentrations in non-pregnant buffaloes were low (<0.20 ng/ml) during the whole experimental period (day 28 to 103), while in pregnant animals plasma PAG levels increased from day 28 (4.48 ± 0.92 ng/ml) until day 41 (27.27 ± 6.74 ng/ml), remaining high (20.71 ± 9.20 ng/ml) until day 103. Progesterone levels were significantly (p < 0.0001) higher in pregnant (3.51–4.80 ng/ml) than in non-pregnant buffaloes (0.28–1.52 ng/ml). A significant difference (p < 0.0001) in plasma PAG concentrations between pregnant and non-pregnant animals starting at day 28 after breeding suggests that PAG-radioimmunoassay could be suitable for pregnancy diagnosis in buffaloes during this period. In conclusion, PAG test offers the advantages that it requires a single plasma sample for early pregnancy diagnosis as well as the accuracy of the test for the detection of pregnancy as early as day 28.     

Untersuchungen zur Verbreitung und Lebensweise von Fledermäusen in Nistkästen im Geisenfelder Forst,Oberbayern

Studies on the distribution and bionomy of bats settled in nest boxes in the forests of Geisenfeld, Upper Bavaria In spring, summer and autumn of 1976 a number of 608 nest boxes constructed as well for birds (554) as for bats (54) hanging in four different wood areas of the Geisenfeld forest was investigated. Two species of bats were found only, the Great Bat,Nyctalus noctula Schreb. (6 Indiv.) and the Long-eared Bat,Plecotus auritus L. (64 Indiv.). The highest number of settlements showed the Thüring bow box with 19%, followed by the Bavarian gable box with 10%. The bats did'nt prefer boxes with horizontal slit, constructed especially for them. By help of a leg hoop fixed in 1959, the age of a femaleP. auritus was stated to 17 years. Both of bat species showed highest trueness to selected locations as to be seen from comparison between former and new results. In deciduous woods no bat was found in the boxes. Here they probable preferred natural holes of old oaks. In deeply (at eye-level) hanging boxes the bats were absent, probable in consequence of disturbing by men. The females and males ofP. auritus were in the ratio of 49 : 11. The highest numbers of females fertilized and aggregated for maternity were 12, 7, 6, 4, and 4 respectively. The average number of bats per check amounted to 23, this resulted in a density of 1 bat per 13 ha. The causes of this low density are to be seen in the low propagation of the bats and particularly in the lack of overwintering holes.