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1.
Data on tsetse fly, and on village Ndama cattle collected over a 4-year period in southern Senegal, were analysed. A total of 431 Ndama cattle in four herds of three villages in the Upper Casamance area of southern Senegal were monitored monthly. Glossina morsitans submorsitans and Glossina palpalis gambiensis are present in the study area. Mean tsetse apparent density was 5.4 flies/trap/day. Trypanosome (Trypanosoma congonlense and Trypanosoma vivax) infection rate in flies was 2.4 (s.e. 0.37)%. Tsetse challenge index was 17.3 (s.e. 4.18). Mean monthly trypanosome prevalence in cattle was 2.5 (s.e. 0.51)%. Highest trypanosome prevalence occurred during the dry season, and animals less than 1-year old were more frequently infected than older animals. The linear relationship between the log10+1 tsetse challenge and the arcsine of the trypanosome prevalence was significant only when mean monthly values of these variables over the 4-year period were used with tsetse challenge preceding infection rate by 3 months. Mean monthly prevalence of strongyle, Strongyloides spp., Toxocara spp. and coccidia were 34.4 (s.e. 0.60), 2.1 (s.e. 0.18), 1.2 (s.e. 0.45) and 15.6 (s.e. 0.47)%, respectively. Calf mortality rate at 1,6 and 12 months of age was 2.1 (s.e. 2.1), 5.2 (s.e. 2.8) and 12.2 (s.e. 3.3)%, respectively. Calving interval (584 s.e. 58 days) was not influenced by trypanosome status of the cow during lactation. Calving interval was shorter by 167 days when the calf died before 1 year of age in comparison to calving intervals for which the calf survived beyond one year. Live weight at birth, 6 and 12 months of age were 15.8 (s.e. 0.54), 48.1 (s.e. 2.56) and 71.1 (s.e. 5.44) kg, respectively. Mean lactation length, total and daily milk offtake were 389 (s.e. 16) days, 231 (s.e. 15) litres and 0.69 (s.e. 0.037) litres, respectively. Trypanosome infection during lactation did not have a significant effect on the amount of milk extracted for human consumption nor did trypanosome status affect calf growth.  相似文献   
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3.
The aim of this study was to evaluate whether the season of ejaculate collection influences seminal quality parameters of pre‐ and post‐freeze–thawing in Xinong Saanen bucks. Ejaculates were collected from eight bucks throughout the four seasons (spring, summer, autumn and winter) in a 12 months’ time period, identified in the Northern Hemisphere. Semen samples were evaluated by the combinations of conventional and Computer‐Assisted Sperm Analysis (CASA) when fresh and after frozen–thawed, respectively. The results clearly demonstrated that season of ejaculate collection influenced (p < 0.05) fresh semen quality. Highest semen quality was observed during autumn. On the contrary, undesirable indices (significantly lower, p < 0.05) were observed in winter as compared with the other remaining seasons. CASA has clearly shown the influences of seasonal variations on semen motility parameters. Furthermore, season of ejaculate collection was also found to influence sperm freezability. Semen characteristics after frozen–thawed followed a similar pattern with that of fresh ejaculate except in spring. The results revealed that sperm quality was higher (p < 0.01) in summer and autumn than in spring and winter. In conclusion, seasonal variation influences semen quality in Xinong Saanen bucks. In addition to summer and autumn, fresh ejaculates in spring can also be successfully used for AI. Sperm from ejaculates collected during summer and autumn are more suitable for cryopreservation. Hence, it is possible to increase the efficiency of goat breeding by manipulating the seasonal variations of semen quality for immediate AI and/or cryopreservation.  相似文献   
4.
RADIOGRAPHIC CHANGES IN TESTES OF BULLS INFECTED WITH BESNOITIOSIS   总被引:1,自引:0,他引:1  
Ten beef bulls infected with Besnoitiosis were examined radiographically and pathologically. Eight of these were slaughtered soon after diagnosis; two were left for a six-month observation period. The radiographic findings were focal and branching-tree calcification of the testes. Histopathologic examination proved these calcifications to be necrotic sections of the seminiferous tubules. Radiography of the testes as a means of evaluating the fertility status of the infected bull is recommended.  相似文献   
5.
With the aim of investigating the relationship between sperm DNA integrity and non‐return rate (NRR) among Norwegian cross‐bred rams, semen from 15 individuals was examined by flow cytometry. Sperm Chromatin Structure Assay (SCSA) quantifies the proportion of spermatozoa with denatured DNA after in situ acid treatment, and the four parameters % DFI, % HDS, MEAN DFI and SD DFI are all different measures of DNA denaturation and maturation. Field fertility, reported as NRR 25 days after insemination was based on all inseminations from a large‐scale breeding programme and supplied by the Norwegian Association of Sheep and Goat Farmers. From each ram, four straws from four different weeks of the breeding season were analysed, and the associations between 25‐day NRR and the mean of the four SCSA parameters were tested using a logistic regression model. The results revealed no association between fertility and % DFI or % HDS, while SD DFI and MEAN DFI showed a significant negative association with NRR. Further, the SCSA values varied significantly between ejaculates within ram among some of the rams in the study. However, no significant association was seen between these intra‐individual differences in sperm DNA integrity and NRR. In conclusion, this study suggests an association between sperm DNA integrity and NRR for rams. However, further research must be conducted to confirm these findings and determine whether sperm DNA assessments can be applied to predict ram fertility.  相似文献   
6.
Global maps of thermal and fast neutron fluxes from the moon suggest three end-member compositional units. A high thermal and low fast neutron flux unit correlates with the lunar highlands and is consistent with feldspathic rocks. The South Pole-Aitken basin and a strip that surrounds the nearside maria have intermediate thermal and fast neutron flux levels, consistent with more mafic rocks. There appears to be a smooth transition between the most mafic and feldspathic compositions, which correspond to low and high surface altitudes, respectively. The maria show low thermal and high fast neutron fluxes, consistent with basaltic rocks.  相似文献   
7.
The Lunar Prospector neutron spectrometer data correlate well with iron and titanium abundances obtained through analysis of Clementine spectral reflectance data. With the iron and titanium dependence removed, the neutron spectrometer data also reveal regions with enhanced amounts of gadolinium and samarium, incompatible rare earth elements that are enriched in the final phases of magma crystallization. These regions are found mainly around the ramparts of the Imbrium impact basin but not around the other basins, including the much larger and deeper South Pole-Aitken basin. This result confirms the compositional uniqueness of the surface and interior of the Imbrium region.  相似文献   
8.
Distilleries produce a huge quantity of effluents, popularly known as spent wash (SW), which when bio-methanated produce post-methanation effluents (PME). A field experiment on soybean–wheat system was conducted for five consecutive years in a Vertisol of central India to evaluate the effect of distillery effluent (DE) on soil carbon and nitrogen dynamics. Ten treatment combinations consisting of control, 100% NPK + Farmyard Manure (FYM), and graded level of SW and PME were applied. Total carbon content of soil increased significantly with applications of FYM and DE. SW was found superior in enhancing carbon content of soil in comparison to PME. Farmyard Manure contributed more carbon toward the recalcitrant pool, whereas DE contributed more carbon toward the active and slow pool. Nitrogen (N) availability was significantly improved with the application of DE. Balanced application of DE may act as amendment for increasing C and N stocks in Vertisol.  相似文献   
9.
The objective of this study was to define the patterns of organogenesis and foetal haemodynamics during the normal gestation of healthy agoutis (Dasyprocta prymnolopha) kept in captivity. Thirty pregnant agoutis that ranged in size from small to medium and weighed between 2.5 and 3 kg underwent B‐mode and Doppler ultrasonography for the biometric evaluation of the foetal organs. The foetal aortic blood flow proved to be predominantly systolic, and the measured flow velocity was 78.89 ± 2.95 cm/s, with a maximum pressure gradient of 2.12 ± 0.27 mmHg. The liver was characterized by its large volume, occupying the entire cranial aspect of the abdominal cavity, and it was associated cranially with the diaphragm and caudally with the stomach. The flow velocity in the portal vein was estimated to equal 12.17 ± 2.37 cm/s, with a resistivity index of 0.82 ± 0.05. The gallbladder was centrally located and protruded cranially towards the diaphragm. The spleen was visualized as an elongated structure with tapered cranial and caudal extremities, and the foetal kidneys were visualized bilaterally in the retroperitoneal region, with the right kidney positioned slightly more cranially than the left. The morphological characterization and hemodynamic analysis of the foetal organs of black‐rumped agoutis via B‐mode and Doppler ultrasonography allow determination of the vascular network and of reference values for the blood flow required for perfusing the anatomical elements essential for maintaining the viability of foetuses at different gestational ages.  相似文献   
10.
Summary

Precocity is particularly important for the economic production of intensively planted apple trees. Unfortunately some cultivars show a propensity for barewood on young trees, which limits early production on 2 year-old spur sites. The new cultivar, ‘Scifresh’ (Jazz?) has shown serious problems of barewood under New Zealand conditions on M.9 and M.26 rootstocks. Barewood has been associated with excessive flowering on feathers and 1 year-old wood. Weak flower clusters develop towards the base of the shoots which do not set fruit and drop off, leaving blind buds. Although there are larger, more well-developed flower clusters on the distal parts of the 1 year-old shoots, cropping these can result in spur extinction. Therefore, in both cases, there is a lack of spur development for the following season resulting in barewood. Experimental treatments have focused on: 1) the effect of timing (January-May) and concentration (400 and 133 mg l–1 gibberellic acid GA3) sprays in the nursery to reduce flowering on 1 year-old wood; and 2) the effect of concentration and timing of localised cytokinin applications in the Spring to re-invigorate blind buds. Two applications of 400 mg l–1 GA3 in late January and late February in the first year in the nursery were effective in eliminating flowering on “knip boom” trees in the following Spring after cutting back. Two applications of 400 mg l–1 GA3, in early and late January, to “knip boom” trees in their second year in the nursery reduced flowering by over 40% when the trees were planted in the orchard. Twelve months later these trees showed an increased density of spur flowers on the original feathers. Aqueous solutions of the cytokinins benzyladenine and thidiazuron, at 500 mg l–1 or 2500 mg l–1 respectively, were applied by brush, prior to, during and post-budbreak, to sections of barewood on 2 year-old or 3 year-old wood on main branches of ‘Scifresh’/M.9 trees. Thidiazuron (at 2500 mg l–1) was far more effective than benzyladenine at inducing growth of dormant buds, even resulting in multiple bud-breaks at individual sites.  相似文献   
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